CVE-2020-6821

HighCVSS 7.5/10Last modified Jun 17, 2026

Description

When reading from areas partially or fully outside the source resource with WebGL's <code>copyTexSubImage</code> method, the specification requires the returned values be zero. Previously, this memory was uninitialized, leading to potentially sensitive data disclosure. This vulnerability affects Thunderbird < 68.7.0, Firefox ESR < 68.7, and Firefox < 75.

Metrics

CVSS 3.1 7.5/10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Weakness enumeration

CWE-908

Affected software

Vendor	Product	Versions
Mozilla	Thunderbird	>= unspecified, < 68.7.0
Mozilla	Firefox ESR	>= unspecified, < 68.7
Mozilla	Firefox	>= unspecified, < 75

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1625404Issue Tracking, Permissions Required
https://usn.ubuntu.com/4335-1/Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2020-12/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-13/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-14/Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1625404Issue Tracking, Permissions Required
https://usn.ubuntu.com/4335-1/Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2020-12/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-13/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-14/Vendor Advisory

Timeline

Published: Apr 24, 2020
Last modified: Jun 17, 2026
NVD status: Modified

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