Microsoft releases eight security bulletins today, updating a set of forty five software vulnerabilities. This month’s updates touch a smaller set of Microsoft software, but two of the Bulletins address kernel-level vulnerabilities and require a restart. Some are being exploited as a part of serious targeted attack activity:
- Windows Kernel, win32k.sys (MS15-061)
- Internet Explorer – critical
- Windows Media Player – critical
- Microsoft Common Controls
- Microsoft Office
- Active Directory Federation Services
- Exchange Server
Two are rated Critical (MS15-056 for Internet Explorer and MS15-057 for Windows Media Player) because of their remote code execution severity. The Internet Explorer bulletin alone fixes over 20 memory corruption vulnerabilities in the IE codebase.
Most interesting of all the bulletins this month turns out to be MS15-061, patching eight different software flaws in the kernel. In particular, cve-2015-2360 was a difficult find, and this 0day was reported by our own talented colleague Maxim Golovkin. This issue presented itself within win32k.sys, which fails to properly free memory after use. It might be rated “Important” as an escalation of privilege vulnerability, but defending against its deployment as a part of targeted attack activity is most certainly critical.
Please update your Windows systems asap.