Microsoft Windows – ‘LoadUvsTable()’ Heap Buffer Overflow
# Date: 15-03-2017 # Author: Hossein Lotfi (https://twitter.com/hosselot) # CVE: CVE-2016-7274 1. Description An integer overflow error within the "LoadUvsTable()" function of usp10.dll can be exploited to cause a heap-based buffer overflow. Full analysis is available at: http://blogs.flexerasoftware.com/secunia-research/2016/12/microsoft_windows_loaduvstable_heap_based_buffer_overflow_vulnerability.html 2. Proof of Concept open “C:\Windows\Fonts\phagspa.ttf” in a hex editor and change the value at offset 0x2051 from 0x00000006 to 0x33333334. 3. Solution: Microsoft initially tried to fixed the issue in MS16-147, but the fix was incomplete and the issue remained unpatched til Microsoft March 2017 patch release: https://twitter.com/hosselot/status/809059287037251584 It appears MS17-013 finally fixed the vulnerability properly: https://technet.microsoft.com/en-us/library/security/ms17-013.aspx @hosselot |