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Improper Restriction of Operations within the Bounds of a Memory Buffer


Severity Medium
Score 5.1/10


The gfxTextRun::SanitizeGlyphRuns function in gfx/thebes/src/gfxFont.cpp in the browser engine in Mozilla Firefox 3.6 before 3.6.2 on Mac OS X, when the Core Text API is used, does not properly perform certain deletions, which allows remote attackers to cause a denial of service (memory corruption and application crash) and possibly execute arbitrary code via an HTML document containing invisible Unicode characters, as demonstrated by the U+FEFF, U+FFF9, U+FFFA, and U+FFFB characters.

  • HIGH
  • NONE

CWE-119 - Buffer Overflow

Buffer overflow attacks involve data transit and operations exceeding the restricted memory buffer, thereby corrupting or overwriting data in adjacent memory locations. Such overflow allows the attacker to run arbitrary code or manipulate the existing code to cause privilege escalation, data breach, denial of service, system crash and even complete system compromise. Given that languages such as C and C++ lack default safeguards against overwriting or accessing data in their memory, applications utilizing these languages are most susceptible to buffer overflows attacks.


Advisory Timeline

  • Published