CVE-2021-29945

The WebAssembly JIT could miscalculate the size of a return type, which could lead to a null read and result in a crash. Note: This issue only affected x86-32 platforms. Other platforms are unaffected.. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.

Weakness

The product performs a calculation that generates incorrect or unintended results that are later used in security-critical decisions or resource management.

Affected Software

Potential Mitigations

• Use languages, libraries, or frameworks that make it easier to handle numbers without unexpected consequences.
• Examples include safe integer handling packages such as SafeInt (C++) or IntegerLib (C or C++).
• Use languages, libraries, or frameworks that make it easier to handle numbers without unexpected consequences.
• Examples include safe integer handling packages such as SafeInt (C++) or IntegerLib (C or C++).

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/128.html
• https://cwe.mitre.org/data/definitions/129.html

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1700690
• https://www.mozilla.org/security/advisories/mfsa2021-14/
• https://www.mozilla.org/security/advisories/mfsa2021-15/
• https://www.mozilla.org/security/advisories/mfsa2021-16/