CVE-2021-21775

A use-after-free vulnerability exists in the way certain events are processed for ImageLoader objects of Webkit WebKitGTK 2.30.4. A specially crafted web page can lead to a potential information leak and further memory corruption. In order to trigger the vulnerability, a victim must be tricked into visiting a malicious webpage.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• http://www.openwall.com/lists/oss-security/2021/07/23/1
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KYMMBQN4PRVDLMIJT2LY2BWHLYBD57P3/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/V4QORERLPDN3UNNJFJSOMHZZCU2G75Q6/
• https://talosintelligence.com/vulnerability_reports/TALOS-2021-1229
• https://www.debian.org/security/2021/dsa-4945
• http://www.openwall.com/lists/oss-security/2021/07/23/1
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KYMMBQN4PRVDLMIJT2LY2BWHLYBD57P3/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/V4QORERLPDN3UNNJFJSOMHZZCU2G75Q6/
• https://talosintelligence.com/vulnerability_reports/TALOS-2021-1229
• https://www.debian.org/security/2021/dsa-4945