On March 7, 2024, the U.S. Cybersecurity & Infrastructure Security Agency (CISA) warned about a remotely exploitable vulnerability with “low attack complexity” in Chirp Systems smart locks.

“Chirp Access improperly stores credentials within its source code, potentially exposing sensitive information to unauthorized access,” CISA’s alert warned, assigning the bug a CVSS (badness) rating of 9.1 (out of a possible 10). “Chirp Systems has not responded to requests to work with CISA to mitigate this vulnerability.”

Matt Brown, the researcher CISA credits with reporting the flaw, is a senior systems development engineer at Amazon Web Services. Brown said he discovered the weakness and reported it to Chirp in March 2021, after the company that manages his apartment building started using Chirp smart locks and told everyone to install Chirp’s app to get in and out of their apartments.

“I use Android, which has a pretty simple workflow for downloading and decompiling the APK apps,” Brown told KrebsOnSecurity. “Given that I am pretty picky about what I trust on my devices, I downloaded Chirp and after decompiling, found that they were storing passwords and private key strings in a file.”

Using those hard-coded credentials, Brown found an attacker could then connect to an application programming interface (API) that Chirp uses which is managed by smart lock vendor August.com, and use that to enumerate and remotely lock or unlock any door in any building that uses the technology.

Update, April 18, 11:55 a.m. ET: August has provided a statement saying it does not believe August or Yale locks are vulnerable to the hack described by Brown.

“We were recently made aware of a vulnerability disclosure regarding access control systems provided by Chirp, using August and Yale locks in multifamily housing,” the company said. “Upon learning of these reports, we immediately and thoroughly investigated these claims. Our investigation found no evidence that would substantiate the vulnerability claims in either our product or Chirp’s as it relates to our systems.”

Update, April 25, 2:45 p.m. ET: Based on feedback from Chirp, CISA has downgraded the severity of this flaw and revised their security advisory to say that the hard-coded credentials do not appear to expose the devices to remote locking or unlocking. CISA says the hardcoded credentials could be used by an attacker within the range of Bluetooth (~30 meters) “to change the configuration settings within the Bluetooth beacon, effectively removing Bluetooth visibility from the device. This does not affect the device’s ability to lock or unlock access points, and access points can still be operated remotely by unauthorized users via other means.”

Brown said when he complained to his leasing office, they sold him a small $50 key fob that uses Near-Field Communications (NFC) to toggle the lock when he brings the fob close to his front door. But he said the fob doesn’t eliminate the ability for anyone to remotely unlock his front door using the exposed credentials and the Chirp mobile app.

Also, the fobs pass the credentials to his front door over the air in plain text, meaning someone could clone the fob just by bumping against him with a smartphone app made to read and write NFC tags.

Neither August nor Chirp Systems responded to requests for comment. It’s unclear exactly how many apartments and other residences are using the vulnerable Chirp locks, but multiple articles about the company from 2020 state that approximately 50,000 units use Chirp smart locks with August’s API.

Roughly a year before Brown reported the flaw to Chirp Systems, the company was bought by RealPage, a firm founded in 1998 as a developer of multifamily property management and data analytics software. In 2021, RealPage was acquired by the private equity giant Thoma Bravo.

Brown said the exposure he found in Chirp’s products is “an obvious flaw that is super easy to fix.”

“It’s just a matter of them being motivated to do it,” he said. “But they’re part of a private equity company now, so they’re not answerable to anybody. It’s too bad, because it’s not like residents of [the affected] properties have another choice. It’s either agree to use the app or move.”

In October 2022, an investigation by ProPublica examined RealPage’s dominance in the rent-setting software market, and that it found “uses a mysterious algorithm to help landlords push the highest possible rents on tenants.”

“For tenants, the system upends the practice of negotiating with apartment building staff,” ProPublica found. “RealPage discourages bargaining with renters and has even recommended that landlords in some cases accept a lower occupancy rate in order to raise rents and make more money. One of the algorithm’s developers told ProPublica that leasing agents had ‘too much empathy’ compared to computer generated pricing.”

Last year, the U.S. Department of Justice threw its weight behind a massive lawsuit filed by dozens of tenants who are accusing the $9 billion apartment software company of helping landlords collude to inflate rents.

In February 2024, attorneys general for Arizona and the District of Columbia sued RealPage, alleging RealPage’s software helped create a rental monopoly.

Last week, Apple pushed out an urgent software update to its flagship iOS platform, warning that there were at least two zero-day exploits for vulnerabilities being used in the wild (CVE-2024-23225 and CVE-2024-23296). The security updates are available in iOS 17.4, iPadOS 17.4, and iOS 16.7.6.

Apple’s macOS Sonoma 14.4 Security Update addresses dozens of security issues. Jason Kitka, chief information security officer at Automox, said the vulnerabilities patched in this update often stem from memory safety issues, a concern that has led to a broader industry conversation about the adoption of memory-safe programming languages [full disclosure: Automox is an advertiser on this site].

On Feb. 26, 2024, the Biden administration issued a report that calls for greater adoption of memory-safe programming languages. On Mar. 4, 2024, Google published Secure by Design, which lays out the company’s perspective on memory safety risks.

Mercifully, there do not appear to be any zero-day threats hounding Windows users this month (at least not yet). Satnam Narang, senior staff research engineer at Tenable, notes that of the 60 CVEs in this month’s Patch Tuesday release, only six are considered “more likely to be exploited” according to Microsoft.

Those more likely to be exploited bugs are mostly “elevation of privilege vulnerabilities” including CVE-2024-26182 (Windows Kernel), CVE-2024-26170 (Windows Composite Image File System (CimFS), CVE-2024-21437 (Windows Graphics Component), and CVE-2024-21433 (Windows Print Spooler).

Narang highlighted CVE-2024-21390 as a particularly interesting vulnerability in this month’s Patch Tuesday release, which is an elevation of privilege flaw in Microsoft Authenticator, the software giant’s app for multi-factor authentication. Narang said a prerequisite for an attacker to exploit this flaw is to already have a presence on the device either through malware or a malicious application.

“If a victim has closed and re-opened the Microsoft Authenticator app, an attacker could obtain multi-factor authentication codes and modify or delete accounts from the app,” Narang said. “Having access to a target device is bad enough as they can monitor keystrokes, steal data and redirect users to phishing websites, but if the goal is to remain stealth, they could maintain this access and steal multi-factor authentication codes in order to login to sensitive accounts, steal data or hijack the accounts altogether by changing passwords and replacing the multi-factor authentication device, effectively locking the user out of their accounts.”

CVE-2024-21334 earned a CVSS (danger) score of 9.8 (10 is the worst), and it concerns a weakness in Open Management Infrastructure (OMI), a Linux-based cloud infrastructure in Microsoft Azure. Microsoft says attackers could connect to OMI instances over the Internet without authentication, and then send specially crafted data packets to gain remote code execution on the host device.

CVE-2024-21435 is a CVSS 8.8 vulnerability in Windows OLE, which acts as a kind of backbone for a great deal of communication between applications that people use every day on Windows, said Ben McCarthy, lead cybersecurity engineer at Immersive Labs.

“With this vulnerability, there is an exploit that allows remote code execution, the attacker needs to trick a user into opening a document, this document will exploit the OLE engine to download a malicious DLL to gain code execution on the system,” Breen explained. “The attack complexity has been described as low meaning there is less of a barrier to entry for attackers.”

A full list of the vulnerabilities addressed by Microsoft this month is available at the SANS Internet Storm Center, which breaks down the updates by severity and urgency.

Finally, Adobe today issued security updates that fix dozens of security holes in a wide range of products, including Adobe Experience Manager, Adobe Premiere Pro, ColdFusion 2023 and 2021, Adobe Bridge, Lightroom, and Adobe Animate. Adobe said it is not aware of active exploitation against any of the flaws.

By the way, Adobe recently enrolled all of its Acrobat users into a “new generative AI feature” that scans the contents of your PDFs so that its new “AI Assistant” can  “understand your questions and provide responses based on the content of your PDF file.” Adobe provides instructions on how to disable the AI features and opt out here.

Top of the heap on this Fat Patch Tuesday is CVE-2024-21412, a “security feature bypass” in the way Windows handles Internet Shortcut Files that Microsoft says is being targeted in active exploits. Redmond’s advisory for this bug says an attacker would need to convince or trick a user into opening a malicious shortcut file.

Researchers at Trend Micro have tied the ongoing exploitation of CVE-2024-21412 to an advanced persistent threat group dubbed “Water Hydra,” which they say has being using the vulnerability to execute a malicious Microsoft Installer File (.msi) that in turn unloads a remote access trojan (RAT) onto infected Windows systems.

The other zero-day flaw is CVE-2024-21351, another security feature bypass — this one in the built-in Windows SmartScreen component that tries to screen out potentially malicious files downloaded from the Web. Kevin Breen at Immersive Labs says it’s important to note that this vulnerability alone is not enough for an attacker to compromise a user’s workstation, and instead would likely be used in conjunction with something like a spear phishing attack that delivers a malicious file.

Satnam Narang, senior staff research engineer at Tenable, said this is the fifth vulnerability in Windows SmartScreen patched since 2022 and all five have been exploited in the wild as zero-days. They include CVE-2022-44698 in December 2022, CVE-2023-24880 in March 2023, CVE-2023-32049 in July 2023 and CVE-2023-36025 in November 2023.

Narang called special attention to CVE-2024-21410, an “elevation of privilege” bug in Microsoft Exchange Server that Microsoft says is likely to be exploited by attackers. Attacks on this flaw would lead to the disclosure of NTLM hashes, which could be leveraged as part of an NTLM relay or “pass the hash” attack, which lets an attacker masquerade as a legitimate user without ever having to log in.

“We know that flaws that can disclose sensitive information like NTLM hashes are very valuable to attackers,” Narang said. “A Russian-based threat actor leveraged a similar vulnerability to carry out attacks – CVE-2023-23397 is an Elevation of Privilege vulnerability in Microsoft Outlook patched in March 2023.”

Microsoft notes that prior to its Exchange Server 2019 Cumulative Update 14 (CU14), a security feature called Extended Protection for Authentication (EPA), which provides NTLM credential relay protections, was not enabled by default.

“Going forward, CU14 enables this by default on Exchange servers, which is why it is important to upgrade,” Narang said.

Rapid7’s lead software engineer Adam Barnett highlighted CVE-2024-21413, a critical remote code execution bug in Microsoft Office that could be exploited just by viewing a specially-crafted message in the Outlook Preview pane.

“Microsoft Office typically shields users from a variety of attacks by opening files with Mark of the Web in Protected View, which means Office will render the document without fetching potentially malicious external resources,” Barnett said. “CVE-2024-21413 is a critical RCE vulnerability in Office which allows an attacker to cause a file to open in editing mode as though the user had agreed to trust the file.”

Barnett stressed that administrators responsible for Office 2016 installations who apply patches outside of Microsoft Update should note the advisory lists no fewer than five separate patches which must be installed to achieve remediation of CVE-2024-21413; individual update knowledge base (KB) articles further note that partially-patched Office installations will be blocked from starting until the correct combination of patches has been installed.

It’s a good idea for Windows end-users to stay current with security updates from Microsoft, which can quickly pile up otherwise. That doesn’t mean you have to install them on Patch Tuesday. Indeed, waiting a day or three before updating is a sane response, given that sometimes updates go awry and usually within a few days Microsoft has fixed any issues with its patches. It’s also smart to back up your data and/or image your Windows drive before applying new updates.

For a more detailed breakdown of the individual flaws addressed by Microsoft today, check out the SANS Internet Storm Center’s list. For those admins responsible for maintaining larger Windows environments, it often pays to keep an eye on Askwoody.com, which frequently points out when specific Microsoft updates are creating problems for a number of users.

In May 2018, the Internet Corporation for Assigned Names and Numbers (ICANN) — the nonprofit entity that manages the global domain name system — instructed all registrars to redact the customer’s name, address, phone number and email from WHOIS, the system for querying databases that store the registered users of domain names and blocks of Internet address ranges.

ICANN made the policy change in response to the General Data Protection Regulation (GDPR), a law enacted by the European Parliament that requires companies to gain affirmative consent for any personal information they collect on people within the European Union. In the meantime, registrars were to continue collecting the data but not publish it, and ICANN promised it would develop a system that facilitates access to this information.

At the end of November 2023, ICANN launched the Registration Data Request Service (RDRS), which is designed as a one-stop shop to submit registration data requests to participating registrars. This video from ICANN walks through how the system works.

Accredited registrars don’t have to participate, but ICANN is asking all registrars to join and says participants can opt out or stop using it at any time. ICANN contends that the use of a standardized request form makes it easier for the correct information and supporting documents to be provided to evaluate a request.

ICANN says the RDRS doesn’t guarantee access to requested registration data, and that all communication and data disclosure between the registrars and requestors takes place outside of the system. The service can’t be used to request WHOIS data tied to country-code top level domains (CCTLDs), such as those ending in .de (Germany) or .nz (New Zealand), for example.

The RDRS portal.

As Catalin Cimpanu writes for Risky Business News, currently investigators can file legal requests or abuse reports with each individual registrar, but the idea behind the RDRS is to create a place where requests from “verified” parties can be honored faster and with a higher degree of trust.

The registrar community generally views public WHOIS data as a nuisance issue for their domain customers and an unwelcome cost-center. Privacy advocates maintain that cybercriminals don’t provide their real information in registration records anyway, and that requiring WHOIS data to be public simply causes domain registrants to be pestered by spammers, scammers and stalkers.

Meanwhile, security experts argue that even in cases where online abusers provide intentionally misleading or false information in WHOIS records, that information is still extremely useful in mapping the extent of their malware, phishing and scamming operations. What’s more, the overwhelming majority of phishing is performed with the help of compromised domains, and the primary method for cleaning up those compromises is using WHOIS data to contact the victim and/or their hosting provider.

Anyone looking for copious examples of both need only to search this Web site for the term “WHOIS,” which yields dozens of stories and investigations that simply would not have been possible without the data available in the global WHOIS records.

KrebsOnSecurity remains doubtful that participating registrars will be any more likely to share WHOIS data with researchers just because the request comes through ICANN. But I look forward to being wrong on this one, and will certainly mention it in my reporting if the RDRS proves useful.

Regardless of whether the RDRS succeeds or fails, there is another European law that takes effect in 2024 which is likely to place additional pressure on registrars to respond to legitimate WHOIS data requests. The new Network and Information Security Directive (NIS2), which EU member states have until October 2024 to implement, requires registrars to keep much more accurate WHOIS records, and to respond within as little as 24 hours to WHOIS data requests tied everything from phishing, malware and spam to copyright and brand enforcement.

The zero-day threats targeting Microsoft this month include CVE-2023-36025, a weakness that allows malicious content to bypass the Windows SmartScreen Security feature. SmartScreen is a built-in Windows component that tries to detect and block malicious websites and files. Microsoft’s security advisory for this flaw says attackers could exploit it by getting a Windows user to click on a booby-trapped link to a shortcut file.

Kevin Breen, senior director of threat research at Immersive Labs, said emails with .url attachments or logs with processes spawning from .url files “should be a high priority for threat hunters given the active exploitation of this vulnerability in the wild.”

The second zero day this month is CVE-2023-36033, which is a vulnerability in the “DWM Core Library” in Microsoft Windows that was exploited in the wild as a zero day and publicly disclosed prior to patches being available. It affects Microsoft Windows 10 and later, as well as Microsoft Windows Server 2019 and subsequent versions.

“This vulnerability can be exploited locally, with low complexity and without needing high-level privileges or user interaction,” said Mike Walters, president and co-founder of the security firm Action1. “Attackers exploiting this flaw could gain SYSTEM privileges, making it an efficient method for escalating privileges, especially after initial access through methods like phishing.”

The final zero day in this month’s Patch Tuesday is a problem in the “Windows Cloud Files Mini Filter Driver” tracked as CVE-2023-36036 that affects Windows 10 and later, as well as Windows Server 2008 at later. Microsoft says it is relatively straightforward for attackers to exploit CVE-2023-36036 as a way to elevate their privileges on a compromised PC.

Beyond the zero day flaws, Breen said organizations running Microsoft Exchange Server should prioritize several new Exchange patches, including CVE-2023-36439, which is a bug that would allow attackers to install malicious software on an Exchange server. This weakness technically requires the attacker to be authenticated to the target’s local network, but Breen notes that a pair of phished Exchange credentials will provide that access nicely.

“This is typically achieved through social engineering attacks with spear phishing to gain initial access to a host before searching for other vulnerable internal targets – just because your Exchange Server doesn’t have internet-facing authentication doesn’t mean it’s protected,” Breen said.

Breen said this vulnerability goes hand in hand with three other Exchange bugs that Microsoft designated as “exploitation more likely:” CVE-2023-36050, CVE-2023-36039 and CVE-2023-36035.

Finally, the SANS Internet Storm Center points to two additional bugs patched by Microsoft this month that aren’t yet showing signs of active exploitation but that were made public prior to today and thus deserve prioritization. Those include: CVE-2023-36038, a denial of service vulnerability in ASP.NET Core, with a CVSS score of 8.2; and CVE-2023-36413: A Microsoft Office security feature bypass. Exploiting this vulnerability will bypass the protected mode when opening a file received via the web.

Windows users, please consider backing up your data and/or imaging your system before applying any updates. And feel free to sound off in the comments if you experience any difficulties as a result of these patches.

Apple last week shipped emergency updates in iOS 17.0.3 and iPadOS 17.0.3 in response to active attacks. The patch fixes CVE-2023-42724, which attackers have been using in targeted attacks to elevate their access on a local device.

Apple said it also patched CVE-2023-5217, which is not listed as a zero-day bug. However, as Bleeping Computer pointed out, this flaw is caused by a weakness in the open-source “libvpx” video codec library, which was previously patched as a zero-day flaw by Google in the Chrome browser and by Microsoft in Edge, Teams, and Skype products. For anyone keeping count, this is the 17th zero-day flaw that Apple has patched so far this year.

Fortunately, the zero-days affecting Microsoft customers this month are somewhat less severe than usual, with the exception of CVE-2023-44487. This weakness is not specific to Windows but instead exists within the HTTP/2 protocol used by the World Wide Web: Attackers have figured out how to use a feature of HTTP/2 to massively increase the size of distributed denial-of-service (DDoS) attacks, and these monster attacks reportedly have been going on for several weeks now.

Amazon, Cloudflare and Google all released advisories today about how they’re addressing CVE-2023-44487 in their cloud environments. Google’s Damian Menscher wrote on Twitter/X that the exploit — dubbed a “rapid reset attack” — works by sending a request and then immediately cancelling it (a feature of HTTP/2). “This lets attackers skip waiting for responses, resulting in a more efficient attack,” Menscher explained.

Natalie Silva, lead security engineer at Immersive Labs, said this flaw’s impact to enterprise customers could be significant, and lead to prolonged downtime.

“It is crucial for organizations to apply the latest patches and updates from their web server vendors to mitigate this vulnerability and protect against such attacks,” Silva said. In this month’s Patch Tuesday release by Microsoft, they have released both an update to this vulnerability, as well as a temporary workaround should you not be able to patch immediately.”

Microsoft also patched zero-day bugs in Skype for Business (CVE-2023-41763) and Wordpad (CVE-2023-36563). The latter vulnerability could expose NTLM hashes, which are used for authentication in Windows environments.

“It may or may not be a coincidence that Microsoft announced last month that WordPad is no longer being updated, and will be removed in a future version of Windows, although no specific timeline has yet been given,” said Adam Barnett, lead software engineer at Rapid7. “Unsurprisingly, Microsoft recommends Word as a replacement for WordPad.”

Other notable bugs addressed by Microsoft include CVE-2023-35349, a remote code execution weakness in the Message Queuing (MSMQ) service, a technology that allows applications across multiple servers or hosts to communicate with each other. This vulnerability has earned a CVSS severity score of 9.8 (10 is the worst possible). Happily, the MSMQ service is not enabled by default in Windows, although Immersive Labs notes that Microsoft Exchange Server can enable this service during installation.

Speaking of Exchange, Microsoft also patched CVE-2023-36778,  a vulnerability in all current versions of Exchange Server that could allow attackers to run code of their choosing. Rapid7’s Barnett said successful exploitation requires that the attacker be on the same network as the Exchange Server host, and use valid credentials for an Exchange user in a PowerShell session.

For a more detailed breakdown on the updates released today, see the SANS Internet Storm Center roundup. If today’s updates cause any stability or usability issues in Windows, AskWoody.com will likely have the lowdown on that.

Please consider backing up your data and/or imaging your system before applying any updates. And feel free to sound off in the comments if you experience any difficulties as a result of these patches.

In a blog post published last month, Cisco Talos said it was seeing a worrisome “increase in the rate of high-sophistication attacks on network infrastructure.” Cisco’s warning comes amid a flurry of successful data ransom and state-sponsored cyber espionage attacks targeting some of the most well-defended networks on the planet.

But despite their increasing complexity, a great many initial intrusions that lead to data theft could be nipped in the bud if more organizations started looking for the telltale signs of newly-arrived cybercriminals behaving like network tourists, Cisco says.

“One of the most important things to talk about here is that in each of the cases we’ve seen, the threat actors are taking the type of ‘first steps’ that someone who wants to understand (and control) your environment would take,” Cisco’s Hazel Burton wrote. “Examples we have observed include threat actors performing a ‘show config,’ ‘show interface,’ ‘show route,’ ‘show arp table’ and a ‘show CDP neighbor.’ All these actions give the attackers a picture of a router’s perspective of the network, and an understanding of what foothold they have.”

Cisco’s alert concerned espionage attacks from China and Russia that abused vulnerabilities in aging, end-of-life network routers. But at a very important level, it doesn’t matter how or why the attackers got that initial foothold on your network.

It might be zero-day vulnerabilities in your network firewall or file-transfer appliance. Your more immediate and primary concern has to be: How quickly can you detect and detach that initial foothold?

The same tourist behavior that Cisco described attackers exhibiting vis-a-vis older routers is also incredibly common early on in ransomware and data ransom attacks — which often unfurl in secret over days or weeks as attackers methodically identify and compromise a victim’s key network assets.

These virtual hostage situations usually begin with the intruders purchasing access to the target’s network from dark web brokers who resell access to stolen credentials and compromised computers. As a result, when those stolen resources first get used by would-be data thieves, almost invariably the attackers will run a series of basic commands asking the local system to confirm exactly who and where they are on the victim’s network.

This fundamental reality about modern cyberattacks — that cybercriminals almost always orient themselves by “looking up” who and where they are upon entering a foreign network for the first time — forms the business model of an innovative security company called Thinkst, which gives away easy-to-use tripwires or “canaries” that can fire off an alert whenever all sorts of suspicious activity is witnessed.

“Many people have pointed out that there are a handful of commands that are overwhelmingly run by attackers on compromised hosts (and seldom ever by regular users/usage),” the Thinkst website explains. “Reliably alerting when a user on your code-sign server runs whoami.exe can mean the difference between catching a compromise in week-1 (before the attackers dig in) and learning about the attack on CNN.”

These canaries — or “canary tokens” — are meant to be embedded inside regular files, acting much like a web beacon or web bug that tracks when someone opens an email.

The Canary Tokens website from Thinkst Canary lists nearly two-dozen free customizable canaries.

“Imagine doing that, but for file reads, database queries, process executions or patterns in log files,” the Canary Tokens documentation explains. “Canarytokens does all this and more, letting you implant traps in your production systems rather than setting up separate honeypots.”

Thinkst operates alongside a burgeoning industry offering so-called “deception” or “honeypot” services — those designed to confuse, disrupt and entangle network intruders. But in an interview with KrebsOnSecurity, Thinkst founder and CEO Haroon Meer said most deception techniques involve some degree of hubris.

“Meaning, you’ll have deception teams in your network playing spy versus spy with people trying to break in, and it becomes this whole counterintelligence thing,” Meer said. “Nobody really has time for that. Instead, we are saying literally the opposite: That you’ve probably got all these [security improvement] projects that are going to take forever. But while you’re doing all that, just drop these 10 canaries, because everything else is going to take a long time to do.”

The idea here is to lay traps in sensitive areas of your network or web applications where few authorized users should ever trod. Importantly, the canary tokens themselves are useless to an attacker. For example, that AWS canary token sure looks like the digital keys to your cloud, but the token itself offers no access. It’s just a lure for the bad guys, and you get an alert when and if it is ever touched.

One nice thing about canary tokens is that Thinkst gives them away for free. Head over to canarytokens.org, and choose from a drop-down menu of available tokens, including:

-a web bug / URL token, designed to alert when a particular URL is visited;
-a DNS token, which alerts when a hostname is requested;
-an AWS token, which alerts when a specific Amazon Web Services key is used;
-a “custom exe” token, to alert when a specific Windows executable file or DLL is run;
-a “sensitive command” token, to alert when a suspicious Windows command is run.
-a Microsoft Excel/Word token, which alerts when a specific Excel or Word file is accessed.

Much like a “wet paint” sign often encourages people to touch a freshly painted surface anyway, attackers often can’t help themselves when they enter a foreign network and stumble upon what appear to be key digital assets, Meer says.

“If an attacker lands on your server and finds a key to your cloud environment, it’s really hard for them not to try it once,” Meer said. “Also, when these sorts of actors do land in a network, they have to orient themselves, and while doing that they are going to trip canaries.”

Meer says canary tokens are as likely to trip up attackers as they are “red teams,” security experts hired or employed by companies seeking to continuously probe their own computer systems and networks for security weaknesses.

“The concept and use of canary tokens has made me very hesitant to use credentials gained during an engagement, versus finding alternative means to an end goal,” wrote Shubham Shah, a penetration tester and co-founder of the security firm Assetnote. “If the aim is to increase the time taken for attackers, canary tokens work well.”

Thinkst makes money by selling Canary Tools, which are honeypots that emulate full blown systems like Windows servers or IBM mainframes. They deploy in minutes and include a personalized, private Canarytoken server.

“If you’ve got a sophisticated defense team, you can start putting these things in really interesting places,” Meer said. “Everyone says their stuff is simple, but we obsess over it. It’s really got to be so simple that people can’t mess it up. And if it works, it’s the best bang for your security buck you’re going to get.”

Further reading:

Dark Reading: Credential Canaries Create Minefield for Attackers
NCC Group: Extending a Thinkst Canary to Become an Interactive Honeypot
Cruise Automation’s experience deploying canary tokens

Six of the flaws fixed today earned Microsoft’s “critical” rating, meaning malware or miscreants could use them to install software on a vulnerable Windows system without any help from users.

Last month, Microsoft acknowledged a series of zero-day vulnerabilities in a variety of Microsoft products that were discovered and exploited in-the-wild attacks. They were assigned a single placeholder designation of CVE-2023-36884.

Satnam Narang, senior staff research engineer at Tenable, said the August patch batch addresses CVE-2023-36884, which involves bypassing the Windows Search Security feature.

“Microsoft also released ADV230003, a defense-in-depth update designed to stop the attack chain associated that leads to the exploitation of this CVE,” Narang said. “Given that this has already been successfully exploited in the wild as a zero-day, organizations should prioritize patching this vulnerability and applying the defense-in-depth update as soon as possible.”

Redmond patched another flaw that is already seeing active attacks — CVE-2023-38180 — a weakness in .NET and Visual Studio that leads to a denial-of-service condition on vulnerable servers.

“Although the attacker would need to be on the same network as the target system, this vulnerability does not require the attacker to have acquired user privileges,” on the target system, wrote Nikolas Cemerikic, cyber security engineer at Immersive Labs.

Narang said the software giant also patched six vulnerabilities in Microsoft Exchange Server, including CVE-2023-21709, an elevation of privilege flaw that was assigned a CVSSv3 (threat) score of 9.8 out of a possible 10, even though Microsoft rates it as an important flaw, not critical.

“An unauthenticated attacker could exploit this vulnerability by conducting a brute-force attack against valid user accounts,” Narang said. “Despite the high rating, the belief is that brute-force attacks won’t be successful against accounts with strong passwords. However, if weak passwords are in use, this would make brute-force attempts more successful. The remaining five vulnerabilities range from a spoofing flaw and multiple remote code execution bugs, though the most severe of the bunch also require credentials for a valid account.”

Experts at security firm Automox called attention to CVE-2023-36910, a remote code execution bug in the Microsoft Message Queuing service that can be exploited remotely and without privileges to execute code on vulnerable Windows 10, 11 and Server 2008-2022 systems. Microsoft says it considers this vulnerability “less likely” to be exploited, and Automox says while the message queuing service is not enabled by default in Windows and is less common today, any device with it enabled is at critical risk.

Separately, Adobe has issued a critical security update for Acrobat and Reader that resolves at least 30 security vulnerabilities in those products. Adobe said it is not aware of any exploits in the wild targeting these flaws. The company also issued security updates for Adobe Commerce and Adobe Dimension.

If you experience glitches or problems installing any of these patches this month, please consider leaving a comment about it below; there’s a fair chance other readers have experienced the same and may chime in here with useful tips.

Additional reading:

-SANS Internet Storm Center listing of each Microsoft vulnerability patched today, indexed by severity and affected component.

–AskWoody.com, which keeps tabs on any developing problems related to the availability or installation of these updates.

On July 10, Apple pushed a “Rapid Security Response” update to fix a code execution flaw in the Webkit browser component built into iOS, iPadOS, and macOS Ventura. Almost as soon as the patch went out, Apple pulled the software because it was reportedly causing problems loading certain websites. MacRumors says Apple will likely re-release the patches when the glitches have been addressed.

Launched in May, Apple’s Rapid Security Response updates are designed to address time-sensitive vulnerabilities, and this is the second month Apple has used it. July marks the sixth month this year that Apple has released updates for zero-day vulnerabilities — those that get exploited by malware or malcontents before there is an official patch available.

If you rely on Apple devices and don’t have automatic updates enabled, please take a moment to check the patch status of your various iDevices. The latest security update that includes the fix for the zero-day bug should be available in iOS/iPadOS 16.5.1, macOS 13.4.1, and Safari 16.5.2.

On the Windows side, there are at least four vulnerabilities patched this month that earned high CVSS (badness) scores and that are already being exploited in active attacks, according to Microsoft. They include CVE-2023-32049, which is a hole in Windows SmartScreen that lets malware bypass security warning prompts; and CVE-2023-35311 allows attackers to bypass security features in Microsoft Outlook.

The two other zero-day threats this month for Windows are both privilege escalation flaws. CVE-2023-32046 affects a core Windows component called MSHTML, which is used by Windows and other applications, like Office, Outlook and Skype. CVE-2023-36874 is an elevation of privilege bug in the Windows Error Reporting Service.

Many security experts expected Microsoft to address a fifth zero-day flaw — CVE-2023-36884 — a remote code execution weakness in Office and Windows.

“Surprisingly, there is no patch yet for one of the five zero-day vulnerabilities,” said Adam Barnett, lead software engineer at Rapid7. “Microsoft is actively investigating publicly disclosed vulnerability, and promises to update the advisory as soon as further guidance is available.”

Barnett notes that Microsoft links exploitation of this vulnerability with Storm-0978, the software giant’s name for a cybercriminal group based out of Russia that is identified by the broader security community as RomCom.

“Exploitation of CVE-2023-36884 may lead to installation of the eponymous RomCom trojan or other malware,” Barnett said. “[Microsoft] suggests that RomCom / Storm-0978 is operating in support of Russian intelligence operations. The same threat actor has also been associated with ransomware attacks targeting a wide array of victims.”

Microsoft’s advisory on CVE-2023-36884 is pretty sparse, but it does include a Windows registry hack that should help mitigate attacks on this vulnerability. Microsoft has also published a blog post about phishing campaigns tied to Storm-0978 and to the exploitation of this flaw.

Barnett said it’s while it’s possible that a patch will be issued as part of next month’s Patch Tuesday, Microsoft Office is deployed just about everywhere, and this threat actor is making waves.

“Admins should be ready for an out-of-cycle security update for CVE-2023-36884,” he said.

Microsoft also today released new details about how it plans to address the existential threat of malware that is cryptographically signed by…wait for it….Microsoft.

In late 2022, security experts at Sophos, Trend Micro and Cisco warned that ransomware criminals were using signed, malicious drivers in an attempt to evade antivirus and endpoint detection and response (EDR) tools.

In a blog post today, Sophos’s Andrew Brandt wrote that Sophos identified 133 malicious Windows driver files that were digitally signed since April 2021, and found 100 of those were actually signed by Microsoft. Microsoft said today it is taking steps to ensure those malicious driver files can no longer run on Windows computers.

As KrebsOnSecurity noted in last month’s story on malware signing-as-a-service, code-signing certificates are supposed to help authenticate the identity of software publishers, and provide cryptographic assurance that a signed piece of software has not been altered or tampered with. Both of these qualities make stolen or ill-gotten code-signing certificates attractive to cybercriminal groups, who prize their ability to add stealth and longevity to malicious software.

Dan Goodin at Ars Technica contends that whatever Microsoft may be doing to keep maliciously signed drivers from running on Windows is being bypassed by hackers using open source software that is popular with video game cheaters.

“The software comes in the form of two software tools that are available on GitHub,” Goodin explained. “Cheaters use them to digitally sign malicious system drivers so they can modify video games in ways that give the player an unfair advantage. The drivers clear the considerable hurdle required for the cheat code to run inside the Windows kernel, the fortified layer of the operating system reserved for the most critical and sensitive functions.”

Meanwhile, researchers at Cisco’s Talos security team found multiple Chinese-speaking threat groups have repurposed the tools—one apparently called “HookSignTool” and the other “FuckCertVerifyTimeValidity.”

“Instead of using the kernel access for cheating, the threat actors use it to give their malware capabilities it wouldn’t otherwise have,” Goodin said.

For a closer look at the patches released by Microsoft today, check out the always-thorough Patch Tuesday roundup from the SANS Internet Storm Center. And it’s not a bad idea to hold off updating for a few days until Microsoft works out any kinks in the updates: AskWoody.com usually has the lowdown on any patches that may be causing problems for Windows users.

And as ever, please consider backing up your system or at least your important documents and data before applying system updates. If you encounter any problems with these updates, please drop a note about it here in the comments.

June’s Patch Tuesday features updates to plug at least 70 security holes, and while none of these are reported by Microsoft as exploited in-the-wild yet, Redmond has flagged several in particular as “more likely to be exploited.”

Top of the list on that front is CVE-2023-29357, which is a “critical” bug in Microsoft SharePoint Server that can be exploited by an unauthenticated attacker on the same network. This SharePoint flaw earned a CVSS rating of 9.8 (10.0 is the most dangerous).

“An attacker able to gain admin access to an internal SharePoint server could do a lot of harm to an organization,” said Kevin Breen, director of cyber threat research at Immersive Labs. “Gaining access to sensitive and privileged documents, stealing and deleting documents as part of a ransomware attack or replacing real documents with malicious copies to further infect users in the organization.”

There are at least three other vulnerabilities fixed this month that earned a collective 9.8 CVSS score, and they all concern a widely-deployed component called the Windows Pragmatic General Multicast (PGM), which is used for delivering multicast data — such as video streaming or online gaming.

Security firm Action1 says all three bugs (CVE-2023-32015, CVE-2023-32014, and CVE-2023-29363) can be exploited over the network without requiring any privileges or user interaction, and affected systems include all versions of Windows Server 2008 and later, as well as Windows 10 and later.

It wouldn’t be a proper Patch Tuesday if we also didn’t also have scary security updates for organizations still using Microsoft Exchange for email. Breen said this month’s Exchange bugs (CVE-2023-32031 and CVE-2023-28310) closely mirror the vulnerabilities identified as part of ProxyNotShell exploits, where an authenticated user in the network could exploit a vulnerability in the Exchange to gain code execution on the server.

Breen said while Microsoft’s patch notes indicate that an attacker must already have gained access to a vulnerable host in the network, this is typically achieved through social engineering attacks with spear phishing to gain initial access to a host before searching for other internal targets.

“Just because your Exchange server doesn’t have internet-facing authentication doesn’t mean it’s protected,” Breen said, noting that Microsoft says the Exchange flaws are not difficult for attackers to exploit.

For a closer look at the patches released by Microsoft today and indexed by severity and other metrics, check out the always-useful Patch Tuesday roundup from the SANS Internet Storm Center. And it’s not a bad idea to hold off updating for a few days until Microsoft works out any kinks in the updates: AskWoody.com usually has the lowdown on any patches that may be causing problems for Windows users.

As always, please consider backing up your system or at least your important documents and data before applying system updates. And if you run into any problems with these updates, please drop a note about it here in the comments.