Adobe will take four weeks before it patches a critical vulnerability in Adobe Reader and Adobe Acrobat - its PDF viewing and editing software, though attack code is in the wild.
Adobe's plan to patch next month means that most users will be at risk until then, as researchers have already crafted a working, if not always reliable, exploit for the vulnerability.
HD Moore, the creator of the open-source Metasploit penetration testing framework, and chief security officer for security company Rapid7, said yesterday that he had worked up attack code for the Reader/Acrobat zero-day bug. "We managed to get the exploit sorted out faster than I thought," said Moore in an email to Computerworld yesterday. "It's now available through the online update feature of Metasploit."
He also announced the exploit module's availability via his Twitter feed.
The exploit is not 100% reliable, however. In a reply to a tweet asking why the Metasploit exploit module wasn't working for one user, Moore explained: "tricky bug and some non-English locale's overlap with the heap spray, we should have an update soon."
Unlike other penetration testing frameworks - such as CANVAS, which is developed by Miami Beach-based Immunity - the open-source Metasploit doesn't charge for its exploits. That lets hackers, as well as legitimate security researchers, get their hands on working attack code.
The appearance of an exploit on Metasploit increases the chance that widespread attacks will begin, said Joshua Talbot, a security intelligence manager in Symantec's security response team. "An exploit in Metasploit lets hackers build on that code," said Talbot, referring to the leg-up attackers receive from Moore's work.
For his part, Moore defended Metasploit's practice of providing working exploits to anyone. "Since the bug is 1) public and 2) widely exploited, we feel that adding an exploit module is the right thing to do, as it provides a safe way for folks to verify that their mitigation efforts actually work," Moore said in a Tuesday email.
Hackers are already exploiting the Adobe bug in the wild, said Symantec's Talbot, although the volume of attacks remains low and the campaign has targeted a relatively small number of people. Those users have received email messages with attached PDF files masquerading as briefing notes or interview requests from the CNN cable news channel.
According to the Contagio malware dump website, which posted several examples of attack messages, the Adobe bug has been actively exploited since at least November 30.
The targeted attacks have used the Reader/Acrobat vulnerability to drop information-stealing malware onto victims' PCs, said Symantec in its technical write-up of the attack code.
When it issues the update next month, Adobe will post it to its security support site.