Security

Adobe on Tuesday released a security bulletin that includes fixes for 28 vulnerabilities in Adobe Reader and Acrobat, including a critical hole that has reportedly been exploited in the wild in limited attacks.

Affected software includes version 9.1.3 of Reader and Acrobat; Acrobat 8.1.6 for Windows, Macintosh, and Unix; and version 7.1.3 of Reader and Acrobat for Windows and Macintosh. The vulnerabilities could cause the applications to crash and could allow an attacker to take control of a user's computer.

Adobe recommends that people update to Adobe Reader 9.2 and Acrobat 9.2, or Acrobat 8.1.7 or Acrobat 7.1.4. For Adobe Reader users who cannot update to Adobe Reader 9.2, Adobe has provided the Adobe Reader 8.1.7 and Adobe Reader 7.1.4 updates.

One of the updates addresses a hole that Trend Micro says has been exploited by a Trojan horse that arrives as a PDF file containing malicious JavaScript. That exploit affects Microsoft Windows 98, ME, NT, 2000, XP, and Server 2003, according to Trend Micro.

"All users of Adobe Reader or Acrobat will need to update their software with today's release because these updates include fixes for the most critical kind of bugs," said Andrew Storms, director of security operations at nCircle.

This is Adobe's second quarterly security update for Adobe Reader and Acrobat.

Also on Tuesday, Microsoft issued a security advisory with a record number of bulletins, including the first fixes for critical holes in Windows 7.

A new zero-day exploit targeting Adobe Reader, as well as 9.1.3 and earlier versions of Adobe Systems' Acrobat, drops a backdoor onto computers using JavaScript, Trend Micro researchers warned on Friday.

Trend Micro identified the exploit as a Trojan horse dubbed "Troj_Pidief.Uo" in a blog post. It arrives as a PDF file containing JavaScript-based malware, "Js_Agent.Dt," and then drops a backdoor called "Bkdr_Protux.Bd."

The exploit affects Microsoft Windows 98, ME, NT, 2000, XP, and Server 2003, according to Trend Micro.

The blog post provides technical details on how the malware works, specifically the activity of its shell code, the piece of code that delivers the payload. The JavaScript is used to execute arbitrary codes in a technique known as "heap spraying."

"Based on our findings, the shell code (that was heap-sprayed) jumps to another shell code inside the PDF file" before extracting and executing the backdoor, Trend Micro said. The backdoor "is also embedded in the PDF file and not the usual file downloaded from the Web."

Variants of the Protux backdoor typically provide an attacker unrestricted user-level access to a compromised machine and previously exploited vulnerabilities in Microsoft Office files, according to Trend Micro.

Adobe announced on Thursday that it would release an update to fix the hole on Tuesday, the same day as Microsoft's Patch Tuesday.

This screenshot shows the embedded executable file in the PDF file, after it has been decrypted.

(Credit: Trend Micro)

If you're a criminal and you want to break into a network, a common attack method is to exploit a hole in software that exists on most computers, has its fair share of holes, and isn't automatically updated.

In 2002, that would have been Windows. Today, it's likely to be Adobe Reader or Flash Player, whose share of vulnerabilities and exploits are on the rise while Microsoft's is falling.

Nearly half of targeted attacks exploit holes in Acrobat Reader, which is used to read PDF (portable document format) files, according to F-Secure. Meanwhile, the number of PDF files used in dangerous Web drive-by attacks jumped from 128 during the first three and a half months of last year to more than 2,300 during that time this year, the company said.

In addition, there are more and more zero-day holes, vulnerabilities that are public before a patch is available. Like sitting ducks, users of affected software are left wide open to attack until a fix is available.

There have been zero-day exploits for the Flash Player plug-in, used for viewing rich media like videos and interactive charts on Web sites. And in one case this spring, a zero-day hole in Adobe Reader spurred security experts to recommend that users disable JavaScript.

One security researcher at Black Hat last week, who asked to remain anonymous, said: "As a result of the number of zero-day attacks on PDFs this year, large banks hate Adobe."

F-Secure said it identified about 1,967 targeted attack files in 2008, the most popular type being .doc used in Microsoft Word.

(Credit: F-Secure)

Those scary statistics prompted F-Secure researcher Mikko Hypponen, chief research officer at F-Secure, to urge Adobe Reader users to switch to an alternative PDF reader at the RSA show in April.

Adobe "has a lot to learn from, of all places, Microsoft," Hypponen said at the time. At the Black Hat and Defcon security shows last week, others concurred.

"Adobe is the next Microsoft," said Roel Schouwenberg, a senior antivirus researcher at Kaspersky. "They are slowly realizing that they have become a main vector of getting into a machine...We as an industry must push hard" to get Adobe to improve security.

An Adobe manager said the problem stems from the fact that it's software is so broadly used.

"It's only natural, given the fact that some of our products like Reader and Flash Player are some of the most widely distributed on Earth, that they would be targeted by attacks," Brad Arkin, director for product security and privacy at Adobe, said in an interview on Wednesday.

Microsoft has been in the same boat, and in many ways still is. The difference is in how the companies respond to the problem, experts said.

Microsoft: Been there, done that
In January 2002, Bill Gates launched the Trustworthy Computing initiative and said security would be a top priority for the company. Microsoft had to do something to combat the negative press and public opinion over its whack-a-mole strategy for countering the viruses and other security holes that plagued its software.

The company established a Security Development Lifecycle program, designed to build security into the software, that has become the standard others in the industry follow. It is roundly lauded for its efforts.

During the first three months of 2009, F-Secure discovered 663 targeted attack files, the most popular type being PDF. The change from the previous year is primarily due to the fact that there have been more vulnerabilities in Adobe Acrobat/Reader than in Microsoft Office, F-Secure said.

(Credit: F-Secure)

Now it's Adobe's turn to step up to the plate.

"Microsoft is a model for patch management...they were forced into it. They really turned around," Hypponen said in an interview last week at Black Hat. "Now, Flash and Reader are ubiquitous and it's harder and harder to target Microsoft, so the attackers are looking for easier targets."

In particular, Adobe's patching process isn't as robust as Microsoft's, he and others said.

In all fairness, Adobe is on the right path. Prompted by a zero-day hole in Reader, Adobe decided in May to start releasing patches on a quarterly basis, and to schedule the updates to coincide with Microsoft's Patch Tuesday releases.

At the time of the Adobe announcement, Arkin said the company was reviewing "everything from our security team's communications during an incident to our security update process to the code itself." He also promised that users would "see more timely communications regarding incidents, quicker turnaround times on patch releases, and simultaneous patches for more affected versions as we move forward."

The company was the first third-party vendor to release a fix for software affected by a vulnerability in Microsoft's Active Template Library, which is used to build components for Web applications and which was being exploited, according to Arkin.

"We scoured the entire Adobe portfolio and evaluated more than 200 products in the field today to determine which might be vulnerable," he said, adding that fixes for Shockwave Player and Flash Player shipped within weeks.

A zero-day exploit targeting Reader and Acrobat that Adobe learned about on April 27 was fixed about two weeks later, he said. And Adobe issued a patch last week for a critical Flash Player problem that was being exploited, allowing attackers to take over a computer via content viewed in a browser.

"We are quite happy with the performance on those," Arkin said of the time frame for the patches.

The company also has been turning an eye toward "digging into legacy code" and looking for additional ways to improve products overall he said. "Adobe integrates the best practices you see at Microsoft and other companies."

The security researcher who asked not to be named complained that at an architectural level, some Adobe applications have too much access to the operating system. "Why should something that operates on untrusted data have full access to your trusted data?" he asked, mentioning specifically Adobe Reader and its ability to access the hard drive to read and write files.

The program's functions require it to be able to save and open files on the file system and thus have read and write access to the hard drive, Arkin said. "Web browsers all have the ability to save to the file system," and the privileges between the two types of programs are similar, he added.

Security-versus-functionality trade-offs aside, changes in Adobe's products and processes will come in response to market pressures and not merely because it's the favorite target for attackers, said Bruce Schneier, chief technology officer of BT Counterpane.

"This is all very much a business decision, whether the company decides to take security seriously or not," he said, adding that he spent his day dealing with Adobe updates.

"I'd like to think that they would start realizing that they can use security as a selling point, but it took Linux to get Microsoft to do that. They felt they had competition," he said. "Is there a Linux waiting to affect Adobe?"

Not really, the experts agreed.

Dan Kaminsky, director of penetration testing at IOActive, praised Adobe for "reconfiguring itself" with regards to security issues and suggested critics should cut the company some slack.

"The PDF exploitation only recently blew up, and remember, it takes any software development house a while to really address problems," he said, adding that Flash 9 was much more secure than Flash 8.

"Does Adobe have products they need to lock down? Yes. Are they in the process of doing so? Yes. They did it for Flash and they'll do it for Reader," he said.

"There's always a 'most vulnerable' attack surface."

Adobe has released a patch for a critical Flash Player problem that could let attackers take over people's computers through content viewed in a browser.

The vulnerability affected a file that shipped with Flash Player 9.x and 10.x for Windows, Mac OS X, and Linux, and with Adobe Reader and Adobe Acrobat 9.x for Windows, Macintosh, and Unix. Adobe said Thursday it fixed the problem in a security advisory, and Adobe's Matt Rozen posted a note on Twitter that directed people to download the patched version from Adobe's Flash download site.

This was no abstract, theoretical vulnerability, either.

"There are reports that this vulnerability is being actively exploited in the wild via limited, targeted attacks against Adobe Reader v9 on Windows," Adobe said in an earlier advisory about the problem.

Flash is very widely used in browsers to power features such as interactive stock charts and YouTube video streaming.

(Credit: Adobe)

Adobe said Thursday that it will issue fixes next week for a critical hole in Flash that is being exploited in attacks against Adobe Reader version 9 on Windows.

The vulnerability exists in current versions of Flash Player for Windows, Macintosh, and Linux and the authplay.dll component that ships with Adobe Reader and Acrobat v9.x for those same platforms, Adobe said in an advisory.

The vulnerability could cause a system to crash or allow an attacker to take control of the computer, Adobe said.

An update for Flash Player v9 and v10 for Windows, Mac, and Linux will be released by July 30, while a fix for Solaris is pending. Adobe should have an update for Reader and Acrobat v9.1.2 for Windows, Macintosh, and Unix by July 31.

An attacker can exploit the vulnerability by luring someone to a Web site hosting a specially crafted Shockwave Flash file, US-CERT said in an advisory Thursday.

"The Adobe Flash browser plug-in is available for multiple Web browsers and operating systems, any of which could be affected," CERT said. "An attacker could also create a PDF document that has an embedded SWF file to exploit the vulnerability. This vulnerability is being actively exploited."

The vulnerabilities can be mitigated by disabling the Flash plug-in or by using the NoScript extension for Mozilla Firefox or SeaMonkey to whitelist sites that can access the Flash plug-in, CERT said.

To disable Flash, US-CERT recommends:

• Disabling Flash in Adobe Reader 9 on Windows platforms by renaming the following files: "%ProgramFiles%\Adobe\Reader 9.0\Reader\authplay.dll" and "%ProgramFiles%\Adobe\Reader 9.0\Reader\rt3d.dll".

• Disabling Flash Player or selectively enabling Flash content as described in the "Securing Your Web Browser" document.

"Deleting, renaming, or removing access to the authplay.dll file that ships with Adobe Reader and Acrobat v9.x mitigates the threat for those products, but users will experience a non-exploitable crash or error message when opening a PDF that contains SWF (Shockwave Flash) content," the Adobe advisory said.

Typically, the authplay.dll that ships with Adobe Reader and Acrobat 9.x for Windows is located at C:\Program Files\Adobe\Reader 9.0\Reader\authplay.dll or C:\Program Files\Adobe\Acrobat 9.0]\Acrobat\authplay.dll, Adobe said.

Windows Vista users can mitigate the impact of the exploit by enabling UAC (User Access Control), according to Adobe. Flash Player users should be careful when browsing unfamiliar Web sites.

Researchers on Wednesday reported that they had uncovered attacks in the wild in which malicious Acrobat PDF files were exploiting a vulnerability in Flash and dropping a Trojan onto computers.

The bug used in the exploit has been around since December 2008.

Researchers on Wednesday said they have uncovered attacks in the wild in which malicious Acrobat PDF files are exploiting a vulnerability in Flash and dropping a Trojan onto computers.

The situation could affect tons of users since Flash exists in all popular browsers, is available in PDF files, and is largely operating system-independent.

Any software that uses Flash could be vulnerable to the attack, according to Symantec. Adobe Reader is vulnerable because its Flash interpreter is vulnerable, said Paul Royal, principal researcher at Purewire, a Web security services provider.

In a post on its Web site, Adobe said it "is aware of reports of a potential vulnerability in Adobe Reader and Acrobat 9.1.2 and Adobe Flash Player 9 and 10. We are currently investigating this potential issue and will have an update once we get more information."

"The authors of the exploit have managed to take a bug and turn it into a reliable exploit using a heap spray technique," Patrick Fitzgerald writes on a Symantec Security blog post.

"Typically an attacker would entice a user to visit a malicious Web site or send a malicious PDF via e-mail," he writes. "Once the unsuspecting user visits the Web site or opens the PDF this exploit will allow further malware to be dropped onto the victim's machine. The malicious PDF files are detected as Trojan.Pidief.G and the dropped files as Trojan Horse."

It appears the exploit was first developed about two weeks ago, Royal said. The bug itself has been around since December 2008.

The hole is exploitable on Windows XP and Vista users are protected if User Account Control (UAC) is enabled, Symantec said.

US-CERT offered information about workarounds on its Web site:

• Disable Flash in Adobe Reader 9 on Windows platforms by renaming the following files: "%ProgramFiles%\Adobe\Reader 9.0\Reader\authplay.dll" and "%ProgramFiles%\Adobe\Reader 9.0\Reader\rt3d.dll".

• Disable Flash Player or selectively enable Flash content as described in the "Securing Your Web Browser" document.

Correction 4:05 p.m. PDT: This post initially misstated how often the security updates will be. Adobe plans to issue updates quarterly.

Adobe said on Wednesday it will release quarterly security updates to coincide with Microsoft's Patch Tuesday as part of a new approach to product security for Adobe Reader and Acrobat.

The security updates will be delivered on a second Tuesday once a quarter, beginning this summer, Brad Arkin, director of product security and privacy, wrote in a blog post. Microsoft's Patch Tuesday updates are issued monthly on the second Tuesday.

Adobe security patches released on Patch Tuesdays March 10 and May 12 were coincidental, the post said.

The most recent patch fixed a hole in Flash Media Server 3.5.1 and earlier that could allow an attacker to execute remote procedures in Flash Media Interactive Server or Flash Media Streaming Server.

The March patch fixed a critical vulnerability in Adobe Reader 9 and Acrobat 9 that could allow an attacker to take complete control of a computer and for which exploits had been reportedly found in the wild for nearly two months.

The Adobe Reader issue sparked "a lot of conversation internally at Adobe from executives to testers and developers" and ultimately led to the permanent changes to Adobe's software security approach, Arkin said. "Everything from our security team's communications during an incident to our security update process to the code itself has been carefully reviewed," he wrote.

All new code and features for Adobe Reader and Acrobat have been put through a Secure product Lifecycle that is similar to Microsoft's much-touted Security Development Lifecycle, according to Arkin. Now, Adobe is working on hardening at-risk areas of its legacy code too, he added.

Arkin also promised that people outside the company "will see more timely communications regarding incidents, quicker turnaround times on patch releases, and simultaneous patches for more affected versions as we move forward."

Security issues with Adobe Reader prompted firm F-Secure to suggest that people should switch to an alternate PDF reader at the RSA security conference last month. Just last month another security hole surfaced in Adobe Reader.

Updated 4:35 p.m. PDT with Adobe saying Windows, Mac and Unix versions of Reader are affected and more details.

Security experts are recommending that people disable JavaScript in Adobe Reader following reports of a vulnerability in the popular portable document format reader on Tuesday.

The vulnerability appears to be due to an error in the "getAnnots()" JavaScript function and exploiting it could allow someone to remotely execute code on the machine, according to an advisory from the US-CERT.

"US-CERT encourages users and administrators to disable JavaScript in Adobe Reader to help mitigate the risk," the post said. "To disable JavaScript in Adobe Reader, open the General Preferences dialog box. From the Edit-Preferences-JavaScript menu, uncheck 'Enable Acrobat JavaScript.'"

All currently supported shipping versions of Adobe Reader (8.1.4, 9.1 and 7.1.1 and earlier) are vulnerable and Windows, Macintosh and Unix platforms are affected, Adobe said in an advisory.

The company said it would release updates for all the platforms but did not yet have a time frame for that. "We are currently not aware of any reports of exploits in the wild for this issue," the advisory said.

At the RSA security conference last week, F-Secure Chief Research Officer Mikko Hypponen said Internet users should switch to using an alternative PDF reader because of the security issues with Adobe Reader. A list of them is available on the PDFReaders.org Web site.

Of the targeted attacks so far this year, more than 47 percent exploit holes in Acrobat Reader, while six vulnerabilities have been discovered that target the program, he said.

Just last month, Adobe issued a fix for an Acrobat Reader hole that attackers had been exploiting for months, after issuing a patch for a critical vulnerability in Flash player the month before.

With all the Internet attacks that exploit Adobe Acrobat Reader people should switch to using an alternative PDF reader, a security expert said at the RSA security conference on Tuesday.

Of the targeted attacks so far this year, more than 47 percent of them exploit holes in Acrobat Reader while six vulnerabilities have been discovered that target the program, Mikko Hypponen, chief research officer of security firm F-Secure, said in a briefing with journalists.

Just last month, Adobe issued a fix for an Acrobat Reader hole that attackers had been exploiting for months, after issuing a patch for a critical vulnerability in Flash player the month before.

In 2008, the favored targeted attack vector was Microsoft Word, which had 15 known vulnerabilities (compared to Acrobat Reader's 19) and which represented 34.5 percent of the attacks (compared to 28.6 percent for Acrobat Reader), he said.

Top-level executives, defense contractors, and other people who have access to specific sensitive corporate or government information are subject to targeted attacks where an attacker sends a file that has malicious code embedded in it. Once the file is opened, the computer is infected typically with a back door that then steals data.

PDF and Flash browser plug-ins are also used in attacks known as "drive-by downloads" in which malware is surreptitiously downloaded onto a computer while the user is surfing the Web. The number of PDF files used in attacks rose from 128 between January 1 and April 16 last year to more than 2,300 in that same time period during this year, said Hypponen.

Adobe should make security a priority, he said.

Adobe "has a lot to learn from, of all places, Microsoft," which offers regular security patches on a monthly basis as part of Patch Tuesday, Hypponen said.

Part of the problem is people don't expect that Acrobat Reader upgrades necessarily contain important security patches like they do with Microsoft software, he said.

Hypponen did not recommend a PDF reader, but said Acrobat Reader alternatives are listed on the PDFReaders.org Web site.