Avast! - Integer Overflow Verifying numFonts in TTC Header
Author: Google Security Research
type: dos
platform: windows
port:
date_added: 2015-12-10
date_updated: 2015-12-10
verified: 1
codes: OSVDB-131561
tags:
aliases:
screenshot_url:
application_url:
Source: https://code.google.com/p/google-security-research/issues/detail?id=549
If the numFonts field in the TTC header is greater than (SIZE_MAX+1) / 4, an integer overflow occurs in filevirus_ttf() when calling CSafeGenFile::SafeLockBuffer.
The TTC file format is described here https://www.microsoft.com/typography/otspec/otff.htm
Proof of Concept:
https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/38934.zip