Adobe on Thursday patched 12 vulnerabilities in Flash Player, including three it inherited from faulty Microsoft development code and one that hackers have been exploiting for at least a week.

In a security advisory published Thursday afternoon, Adobe briefly spelled out the dozen vulnerabilities, 10 that were pegged as potentially leading to hijacked systems or with hackers executing their own malware on a machine.

The vulnerabilities affect the Windows, Mac and Linux versions of Flash Player. Still to patch: the Solaris edition.

Last week, Adobe had promised that it would patch Flash on July 30 after reports surfaced of attacks against both Flash and Adobe Reader, a popular PDF viewer. Hackers have been attacking users running Flash through drive-bys hosted on compromised Web sites, and targeting people running Reader via a bug in the Flash interpreter baked into that program.

Reader and Adobe Acrobat are slated for an update today.

Adobe also took care of three vulnerabilities within Flash that were the result of the company's developers using a buggy Microsoft code "library" when they built the program. On Wednesday, Adobe confirmed that it had used Microsoft's flawed development code -- specifically the Active Template Library (ATL), a code library included with Visual Studio -- to create both Flash Player and Shockwave Player. The latter was patched that same day.

On Tuesday, Microsoft acknowledged that ATL contained multiple vulnerabilities, at least one harking back to early 2008. Although Microsoft patched Visual Studio to eliminate the bugs in ATL, those updates do not fix software developed using the flawed library. Instead, vendors must use the patched Visual Studio to recompile their code, then distribute the new, secure software.

That's what Adobe did yesterday while working a tight schedule.

According to Brad Arkin, Adobe's director for product security and privacy, Microsoft notified his company of the ATL vulnerabilities on July 10, just over two weeks before Microsoft announced the flaws.

That timetable differed from what Microsoft hinted at Tuesday, when Mike Reavey, the director of the company's Security Response Center, said that his security team had been investigating the ATL flaws since early 2008, and had been coordinating with third-party vendors to examine their code for the past several months.

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