The update comes with significant security improvements, including the on-by-default addition "Enhanced Security," a feature that provides a set of default restrictions and a method to define trusted locations that should not be subject to those restrictions. First up, here are the security vulnerabilities patched with this update:
- This update resolves a use-after-free vulnerability in Multimedia.api that could lead to code execution (CVE-2009-4324). This issue is being actively exploited in the wild; the exploit targets Adobe Reader and Acrobat 9.2 on Windows platforms.
- This update resolves an array boundary issue in U3D support that could lead to code execution (CVE-2009-3953).
- This update resolves a DLL-loading vulnerability in 3D that could allow arbitrary code execution (CVE-2009-3954).
- This update resolves a memory corruption vulnerability that could lead to code execution (CVE-2009-3955).
- This update mitigates a script injection vulnerability by changing the Enhanced Security default (CVE-2009-3956).
- This update resolves a null-pointer dereference vulnerability that could lead to denial of service (CVE-2009-3957).
- This update resolves a buffer overflow vulnerability in the Download Manager that could lead to code execution (CVE-2009-3958).
- This update resolves an integer overflow vulnerability in U3D support that could lead to code execution (CVE-2009-3959).
Adobe rates this a "critical" update on all platforms. The flaws affect Adobe Reader 9.2 and Acrobat 9.2 for Windows, Macintosh and UNIX; and Adobe Reader 8.1.7 and Acrobat 8.1.7 for Windows and Macintosh.
These vulnerabilities could cause the application to crash and could potentially allow an attacker to take control of the affected system.
According to this document released alongside the patches, Adobe has turned on the Enhanced Security feature by default.
Enhanced security provides two tools designed to help you protect your environment: a set of default restrictions and a method to define trusted locations that should not be subject to those restrictions. In other words, you can either block dangerous actions altogether or else selectively permit them for locations and files you trust.
It also includes privileged location improvements, cross domain support, warning message and dialog improvements and the disabling of legacy multimedia support by default.
Adobe is also beta testing a new automatic updater for Reader and Acrobat. By default, the updater will silently patch installations without user interaction.