Adobe issued a security update today that patched 29 vulnerabilities in its popular PDF viewing and editing applications, most of them bugs that attackers can use to grab control of personal computers.
The update, Adobe's second since it announced that it would patch Adobe Reader and Adobe Acrobat quarterly -- and on the same day that Microsoft delivers its monthly security updates -- fixed one flaw that hackers have already been using in the wild.
"These vulnerabilities could cause the application to crash and could potentially allow an attacker to take control of the affected system," Adobe acknowledged in the advisory that accompanied the updates to versions 9.2, 8.1.7 and 7.1.4 of both Reader and Acrobat. "Updates apply to all platforms: Windows, Macintosh and UNIX," the advisory added.
Adobe tagged 13 of the 29 bugs with the phrase "could potentially lead to arbitrary code execution," security-speak for vulnerabilities that could be exploited to hijack a system. Like Apple, but unlike Microsoft, Oracle and other large software vendors, Adobe does not apply a rating system to the flaws it fixes.
Four of the bugs may be exploitable, Adobe confirmed, saying that for the quartet, "arbitrary code execution has not been demonstrated, but may be possible."
Many of the rest could be used to crash Reader or Acrobat, but were not likely to lead to a compromised computer.
Last week, Adobe confirmed that one of the vulnerabilities patched today was being exploited using rigged PDF files in "limited targeted attacks," and promised then that it would fix the flaw today.
The backdoor Trojan, dubbed "Protux" by Trend Micro, is no malware newcomer; it's been the payload for attacks that exploited vulnerabilities in Microsoft's Office suite.
Also in the Adobe patch mix today were fixes for the Reader plug-ins used by Mozilla's Firefox, Google's Chrome and Opera Software's Opera browsers. While the Firefox plug-in bug was considered critical, the one in the plug-in used by Chrome and Opera was less serious, although it could be used by identity thieves to hoodwink users into believing they were at a legitimate website when they actually had been shunted to a phony.
Adobe has struggled this year to keep up with a rising tide of Reader and Acrobat vulnerabilities. In March, the company quashed a PDF bug that attackers had been using for more than two months, patched Reader and Acrobat again in May to block another zero-day and fixed a Flash-related PDF flaw in July.
The update was the fourth this year that plugged a hole already being used by hackers.
Although Microsoft patched more vulnerabilities today (34) than did Adobe, at least one researcher pegged the latter as the company that needs to step up its security game.
"The lower-hanging fruit isn't Microsoft, it's Adobe," said Wolfgang Kandek, chief technology officer at security vendor Qualys. "They seem to be getting a decent amount of attacks against their software."
Adobe has made moves to improve its security bottom line, the biggest being a promise in June to follow Microsoft's lead and release regular security updates for Reader and Acrobat. Originally, Adobe intended to post its second quarterly update last month, but a scramble during July to fix several flaws, including some introduced by Microsoft in a code "library" used by Adobe developers, ruined that plan. It announced more than a month ago that it would instead push the patch date into October.
Adobe Reader and Adobe Acrobat 9.2, 8.1.7 and 7.1.4 for Windows, Mac and Linux can be downloaded from Adobe's website using the links included in today's advisory. Alternately, users can use the programs' built-in update mechanism to grab the new versions.