Posts Tagged: zero day


12
Nov 13

Zero-Days Rule November’s Patch Tuesday

Microsoft today issued security updates to fix at least 19 vulnerabilities in its software, including a zero-day flaw in Internet Explorer browser that is already being actively exploited. Separately, Adobe has released a critical update that plugs at least two security holes in its Flash Player software.

crackedwinThree of the eight patches that Microsoft released earned its most dire “critical” label, meaning the vulnerabilities fixed in them can be exploited by malware or miscreants remotely without any help from Windows users. Among the critical patches is an update for Internet Explorer (MS13-088) that mends at least two holes in the default Windows browser (including IE 11). MS13-089 is a critical file handling flaw present in virtually every supported version of Windows.

The final critical patch — MS13-090 — fixes essentially another IE flaw (ActiveX) that showed up in targeted attacks late last week. Microsoft says attackers used a second, “information disclosure” vulnerability in tandem with the ActiveX flaw, but that the company is still investigating that one. It noted that its Enhanced Mitigation Experience Toolkit (EMET) tool successfully blocked the ActiveX exploit.

Nevertheless, it’s important for IE users to apply these updates as quickly as possible. According to Rapid7, exploit code for the ActiveX vulnerability appeared on Pastebin this morning.

“It was known to be under some targeted exploitation, but that will probably expand now that the exploit is public,” said Ross Barrett, senior manager of security engineering at Rapid7. “I would call patching this issue priority #1.” For what it’s worth, Microsoft agrees, at least according to this suggested patch deployment chart.

Today’s patch batch from Redmond did not include an official patch for yet another zero-day vulnerability that has been under active exploitation, although Microsoft did release a stopgap Fix-It tool last week to help blunt the threat. The company also is once again advising Windows users to take another look at EMET.

Check out Microsoft’s Technet blog for more information on these and other updates that the company released today.

brokenflash-aIn a separate patch release, Adobe issued a fix for its Flash Player software for Windows, Mac, Linux and Android devices. The Flash update brings the ubiquitous player to v. 11.9.900.152 on Mac and Windows systems. Users browsing the Web with IE10 or IE11 on Windows 8.x should get the new version of Flash (11.9.900.152) automatically; IE users not on Windows 8 will need to update manually if Flash is not set to auto-update.

To check which version of Flash you have installed, visit this page. Direct links to the various Flash installers are available here. Be aware that downloading Flash Player from Adobe’s recommended spot — this page — often includes add-ons, security scanners or other crud you probably don’t want. Strangely enough, when I visited that page today with IE10 , the download included a pre-checked box to install Google Toolbar and to switch my default browser to Google Chrome.

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6
May 13

Zero-Day Exploit Published for IE8

Security experts are warning that a newly discovered vulnerability in Internet Explorer 8 is being actively exploited to break into Microsoft Windows systems. Complicating matters further, computer code that can be used to reliably exploit the flaw is now publicly available online.

IEwarningIn an advisory released May 3, Microsoft said it was investigating reports of a vulnerability in IE8, and that it was aware of attacks that attempt to exploit this bug. The company stresses that other versions of IE — including IE6, 7, 9 and 10 are not affected by the vulnerability. However, all versions of IE8 are vulnerable, including copies running on Windows XP, Vista and Windows 7.

Meanwhile, a new module that exploits this IE8 bug is now available for the Metasploit Framework, a free penetration testing tool. I would expect this exploit or some version of it will soon be rolled into commercial exploit kits that are sold in the cybercrime underground (assuming this has not already happened).

Update, May 9, 9:00 a.m. ET: Microsoft has released a fix-it tool to blunt attacks on this bug. See this story for more information.

Original post:

The security hole has already been leveraged in at least one high-profile attack. Over the weekend, several security vendors reported that the U.S. Department of Labor Web site had been hacked and seeded with code designed to exploit the flaw and download malicious software.

The attack on the Labor Department site is seen as a watering hole attack, which involves the targeted compromise of legitimate websites thought to be of interest to or frequented by end users who belong to organizations that attackers wish to infiltrate. Previous watering hole attacks have targeted the Web site for the Council on Foreign Relations, the Association of Southeast Asian Nations, and the National Democratic Institute.

According to CrowdStrike, the server used to control this latest attack on the Labor Department site was microsoftupdate.ns1.name. The company said analysis of the logs from the attacker’s infrastructure revealed that visitors from 37 different countries browsed the site during the time it was compromised with the malicious code. AlienVault, Invincea and Cisco Systems have published additional details on this attack. AlienVault also said it has since spotted the same exploit used on at least nine other hacked Web sites, including several non-profit groups and a large European company.

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2
Apr 13

Fool Me Once…

When you’re lurking in the computer crime underground, it pays to watch your back and to keep your BS meter set to  ‘maximum.’ But when you’ve gained access to an elite black market section of a closely guarded crime forum to which very few have access, it’s easy to let your guard down. That’s what I did earlier this year, and it caused me to chase a false story. This blog post aims to set the record straight on that front, and to offer a cautionary (and possibly entertaining) tale to other would-be cybersleuths.

baitOn Jan. 16, 2013, I published a post titled, “New Java Exploit Fetches $5,000 Per Buyer.” The details in that story came from a sales thread posted to an exclusive subforum of Darkode.com, a secretive underground community that has long served as a bazaar for all manner of cybercriminal wares, including exploit kitsspam services, ransomware programs, and stealthy botnets. I’ve maintained a presence on this forum off and on (mostly on) for the past three years, in large part because Darkode has been a reliable place to find information about zero-days, or highly valuable threats that exploit previously unknown vulnerabilities in software — threats that are shared or used by attackers before the developer of the target software knows about the vulnerability.

I had previously broken several other stories about zero-day exploits for sale on Darkode that later showed up “in-the-wild” and confirmed by the affected vendors, and this sales thread was posted by one of the forum’s most trusted members. The sales thread also was created during a time in which Java’s maker Oracle Corp. was struggling with multiple zero-days in Java.

What I didn’t know at the time was that this particular sales thread was little more than a carefully laid trap by the Darkode administrators to discover which accounts I was using to lurk on their forum. Ironically, I recently learned of this snare after white/grey hat hackers compromised virtually all of the administrator accounts and private messages on Darkode.

“Looks like Krebs swallowed the bait, and i got an idea how to catch him now for the next thread,” wrote Darkode administrator “Mafi” in a Jan. 16 private message to a co-admin who uses the nickname “sp3cial1st”.

Following this post, the administrators compared notes as to which users had viewed the fake Java zero-day sales thread during the brief, two-day period it was live on a restricted portion of Darkode. “I have taken a careful examination of the logs related to the java 0day thread,” sp3cial1st wrote to a Darkode administrator who used the nick “187”.

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27
Feb 13

Flash Player Update Fixes Zero-Day Flaws

Adobe has released an emergency update for its Flash Player software that fixes three critical vulnerabilities, two of which the company warns are actively being exploited to compromise systems.

brokenflash-aIn an advisory, Adobe said two of the bugs quashed in this update (CVE-2013-0643 and CVE-2013-0648) are being used by attackers to target Firefox users. The company noted that the attacks are designed to trick users into clicking a link which redirects to a Web site serving malicious Flash content.

Readers can be forgiven for feeling patch fatigue with Flash: This is the third security update that Adobe has shipped for Flash in the last month. On Feb. 12, Adobe released a patch to plug at least 17 security holes in Flash. On Feb. 7, Adobe rushed out an update to fix two other flaws that attackers were already exploiting to break into vulnerable computers.

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20
Feb 13

Critical Security Updates for Adobe Reader, Java

Adobe and Oracle each released updates to fix critical security holes in their software. Adobe’s patch plugs two zero-day holes that hackers have been using to break into computers via Adobe Reader and Acrobat. Separately, Oracle issued updates to correct at least five security issues with Java.

javaiconThe Java update comes amid revelations by Apple, Facebook and Twitter that employees at these organizations were hacked using exploits that attacked Java vulnerabilities on Mac and Windows machines. According to Bloomberg News, at least 40 companies were targeted in malware attacks linked to an Eastern European gang of hackers that has been trying to steal corporate secrets.

Oracle’s update brings Java on Windows systems to Java SE 7 Update 15, and Java 6 Update 41. Most consumers can get by without Java installed, or least not plugged into the browser. Because of the prevalence of threats targeting Java installations, I’d urge these users to remove Java or unplug it from the browser. If this is too much trouble, consider adopting a dual-browser approach, keeping Java unplugged from your main browser, and plugged in to a secondary browser that you only use to visit sites that require the plugin. To find out if you have Java installed, visit java.com and click the “Do I have Java?” link below the big red button. Existing users can update Java from the Java Control Panel, clicking the Update tab and then the “Update Now” button.

Apple has issued an update that brings Java up-to-date on security patches but also disables the Java plugin from Web browsers on the system. Apple also issued a malware removal tool that it said should remove from Macs the most common variants of malware that used the most recent Java exploits. Continue reading →


7
Feb 13

Critical Flash Player Update Fixes 2 Zero-Days

Adobe today pushed out an emergency update that fixes at least two zero-day vulnerabilities in its ubiquitous Flash Player software — flaws that attackers are already exploiting to break into systems. Interestingly, Adobe warns that one of the exploits in use is designed to drop malware on both Windows and Mac OS X systems.

brokenflash-aAdobe said in an advisory that one of the vulnerabilities — CVE-2013-0634 – is being exploited in the wild in attacks delivered via malicious Flash content hosted on websites that target Flash Player in Firefox or Safari on the Macintosh platform, as well as attacks designed to trick Windows users into opening a Microsoft Word document delivered as an email attachment.

Adobe also warned that a separate flaw — CVE-2013-0633 — is being exploited in the wild in targeted attacks designed to trick the user into opening a Microsoft Word document delivered as an email attachment which contains malicious Flash content. The company said the exploit for CVE-2013-0633 targets the ActiveX version of Flash Player on Windows (i.e. Internet Explorer users).

Updates are available for Windows, Mac, Linux and Android users. The latest Windows and Mac version is v. 11.5.502.149, and is available from this link. Those who prefer a direct link to the OS-specific downloads can grab them here. To find out if you have Flash installed and what version your browser may be running, check out this page.

flash115502149

Flash Player installed with Google Chrome should automatically be updated to the latest Google Chrome version, which will include Adobe Flash Player v. 11.5.31.139 for Windows, Macintosh and Linux. Likewise, Internet Explorer 10 for Windows 8 also includes an auto-update feature, which should bring Flash to version 11.3.379.14 for Windows.

Adobe’s advisory notes that the vulnerability that has been used to attack both Mac and Windows users was reported with the help of the Shadowserver Foundation, the federally funded technology research center MITRE Corporation, and aerospace giant Lockheed Martin‘s computer incident response team. No doubt there are some interesting stories about how these attacks were first discovered, and against whom they were initially deployed.


16
Jan 13

New Java Exploit Fetches $5,000 Per Buyer

Less than 24 hours after Oracle patched a dangerous security hole in its Java software that was being used to seize control over Windows PCs, miscreants in the Underweb were already selling an exploit for a different and apparently still-unpatched zero-day vulnerability in Java, KrebsOnSecurity has learned.

javared

Update, Apr. 2, 2:57 p.m. ET: This sales thread turned out to be an elaborate hoax designed by a cybercrime forum administrator to learn the screen name I was using to browse exclusive sections of his forum. See this story for more information on that.

Original story:

On Sunday, Oracle rushed out a fix for a critical bug in Java that had been folded into exploit kits, crimeware made to automate the exploitation of computers via Web browser vulnerabilities. On Monday, an administrator of an exclusive cybercrime forum posted a message saying he was selling a new Java 0day to a lucky two buyers. The cost: starting at $5,000 each.

The hacker forum admin’s message, portions of which are excerpted below, promised weaponized and source code versions of the exploit. This seller also said his Java 0day — in the latest version of Java (Java 7 Update 11) — was not yet part of any exploit kits, including the Cool Exploit Kit I wrote about last week that rents for $10,000 per month. From his sales pitch:

“New Java 0day, selling to 2 people, 5k$ per person

And you thought Java had epically failed when the last 0day came out. I lol’d. The best part is even-though java has failed once again and let users get compromised… guess what? I think you know what I’m going to say… there is yet another vulnerability in the latest version of java 7. I will not go into any details except with seriously interested buyers.

Code will be sold twice (it has been sold once already). It is not present in any known exploit pack including that very private version of [Blackhole] going for 10$k/month. I will accepting counter bids if you wish to outbid the competition. What you get? Unencrypted source files to the exploit (so you can have recrypted as necessary, I would warn you to be cautious who you allow to encrypt… they might try to steal a copy) Encrypted, weaponized version, simply modify the url in the php page that calls up the jar to your own executable url and you are set. You may pm me.” Continue reading →


13
Jan 13

Oracle Ships Critical Security Update for Java

Oracle has released a software update to fix a critical security vulnerability in its Java software that miscreants and malware have been exploiting to break into vulnerable computers.

javanix2Java 7 Update 11 fixes a critical flaw (CVE-2013-0422) in Java 7 Update 10 and earlier versions of Java 7. The update is available via Oracle’s Web site, or can be downloaded from with Java via the Java Control Panel. Existing users should be able to update by visiting the Windows Control Panel and clicking the Java icon, or by searching for “Java” and clicking the “Update Now” button from the Update tab.

This update also changes the way Java handles Web applications. According to Oracle’s advisory: “The default security level for Java applets and web start applications has been increased from “Medium” to “High”. This affects the conditions under which unsigned (sandboxed) Java web applications can run. Previously, as long as you had the latest secure Java release installed applets and web start applications would continue to run as always. With the “High” setting the user is always warned before any unsigned application is run to prevent silent exploitation.”

It’s nice that Oracle fixed this vulnerability so quickly, but I’ll continue to advise readers to junk this program altogether unless they have a specific need for it. For one thing, Oracle tried (and failed) to fix this flaw in an earlier update. Also, it seems malware writers are constantly finding new zero-day vulnerabilities in Java, and I would not be surprised to see this zero-day situation repeat itself in a month or so. Also, most users who have Java installed can get by just fine without it (businesses often have mission-critical operations that rely on Java).

If you need Java for a specific Web site, consider adopting a two-browser approach. If you normally browse the Web with Firefox, for example, consider disabling the Java plugin in Firefox, and then using an alternative browser (Chrome, IE9, Safari, etc.) with Java enabled to browse only the site(s) that require(s) it.


27
Nov 12

Java Zero-Day Exploit on Sale for ‘Five Digits’

Miscreants in the cyber underground are selling an exploit for a previously undocumented security hole in Oracle’s Java software that attackers can use to remotely seize control over systems running the program, KrebsOnSecurity has learned.

The flaw, currently being sold by an established member of an invite-only Underweb forum, targets an unpatched vulnerability in Java JRE 7 Update 9, the most recent version of Java (the seller says this flaw does not exist in Java 6 or earlier versions).

According to the vendor, the weakness resides within the Java class “MidiDevice.Info,” a component of Java that handles audio input and output. “Code execution is very reliable, worked on all 7 version I tested with Firefox and MSIE on Windows 7,” the seller explained in a sales thread on his exploit. It is not clear whether Chrome also is affected. “I will only sell this ONE TIME and I leave no guarantee that it will not be patched so use it quickly.”

The seller was not terribly specific on the price he is asking for this exploit, but set the expected offer at “five digits.” The price of any exploit is ultimately whatever the market will bear, but this is roughly in line with the last Java zero-day exploit that was being traded and sold on the underground. In August, I wrote about a newly discovered Java exploit being folded into the BlackHole exploit kit, quoting the author of that crimeware tool as saying that “the price of such an exploit if it were sold privately would be about $100,000.”

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1
Oct 12

In a Zero-Day World, It’s Active Attacks that Matter

The recent zero-day vulnerability in Internet Explorer caused many (present company included) to urge Internet users to consider surfing the Web with a different browser until Microsoft issued a patch. Microsoft did so last month, but not before experts who ought to have known better began downplaying such advice, pointing out that other browser makers have more vulnerabilities and just as much exposure to zero-day flaws.

This post examines hard data that shows why such reasoning is more emotional than factual. Unlike Google Chrome and Mozilla Firefox users, IE users were exposed to active attacks against unpatched, critical vulnerabilities for months at a time over the past year and a half.

Attackers exploited zero-day holes in Internet Explorer for at least 89 days over the past 19 months.

The all-browsers-are-equally-exposed argument was most recently waged by Trend Micro‘s Rik Ferguson. Ferguson charges that it’s unfair and unrealistic to expect IE users to switch — however briefly — to experiencing the Web with an alternative browser. After all, he says, the data show that other browsers are similarly dogged by flaws, and switching offers no additional security benefits. To quote Ferguson:

“According to this blog post, in 2011 Google’s Chrome had an all time high of 275 new vulnerabilities reported, the current peak of an upward trend since its day of release. Mozilla Firefox, while currently trending down from its 2009 high, still had a reported 97 vulnerabilities. Microsoft’s Internet Explorer has been trending gradually down for the past five years and 2011 saw only 45 new vulnerabilities, less than any other browser except Apple’s Safari, which also had 45. Of course raw numbers of vulnerabilities are almost meaningless unless we consider the respective severity, but there again, of the ‘big three’ the statistics favour Internet Explorer. If zero-day vulnerabilities have to be taken into consideration too, they don’t really do much to change the balance, Google Chrome 6, Microsoft Internet Explorer 6 and Mozilla Firefox 4. Of course different sources offer completely different statistics, and simple vulnerability counts are no measure of relative (in)security of browsers, particularly in isolation. However, it cannot be ignored that vulnerabilities exist in every browser.”

Looking closer, we find that this assessment does not hold water. For one thing, while Ferguson acknowledges that attempting to rate the relative security of similar software products by merely comparing vulnerabilities is not very useful, he doesn’t offer much more perspective. He focuses on unpatched, publicly-highlighted vulnerabilities, but he forgets to ask and answer a crucial question: How do browser makers rate in terms of unpatched vulnerabilities that are actively being exploited?

Part of the problem here is that many security pundits rank vulnerabilities as “zero-day” as long as they are both publicly identified and unfixed. Whether there is evidence that anyone is actually attacking these vulnerabilities seems beside the point for this camp. But I would argue active exploitation is the most important qualifier of a true zero-day, and that the software flaws most worthy of worry and action by users are those that are plainly being exploited by attackers.

To that end, I looked back at the vulnerabilities fixed since January 2011 by Google, Microsoft and Mozilla, with an eye toward identifying true zero-day flaws that were identified publicly as being exploited before the vendor issued a software patch. I also queried both Mozilla and Google to find out if I had missed anything in my research.

As Ferguson mentioned, all browser makers had examples over the past 19 months of working or proof-of-concept exploit code available for unpatched flaws in their products. However, both my own investigation and the public record show that of the three browsers, Internet Explorer was the only one that had critical, unpatched vulnerabilities that were demonstrably exploited by attackers before patches were made available. According to Microsoft’s own account, there were at least six zero-days actively exploited in the past 18 months in IE. All but one of them earned Microsoft’s most dire “critical” rating, leaving IE users under zero-day attack for at least 152 days since the beginning of 2011.

If we count just the critical zero-days, there were at least 89 non-overlapping days (about three months) between the beginning of 2011 and Sept. 2012 in which IE zero-day vulnerabilities were actively being exploited. That number is almost certainly conservative, because I could find no data on the window of vulnerability for CVE-2011-0094, a critical zero-day flaw fixed in MS11-018 that Microsoft said was being attacked prior to releasing a patch for it. This analysis also does not include CVE-2011-1345, a vulnerability demonstrated at the Pwn2Pwn contest in 2011.

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