CVE-2021-29969

If Thunderbird was configured to use STARTTLS for an IMAP connection, and an attacker injected IMAP server responses prior to the completion of the STARTTLS handshake, then Thunderbird didn't ignore the injected data. This could have resulted in Thunderbird showing incorrect information, for example the attacker could have tricked Thunderbird to show folders that didn't exist on the IMAP server. This vulnerability affects Thunderbird < 78.12.

• CWE-552

• https://bugzilla.mozilla.org/show_bug.cgi?id=1682370Issue Tracking, Permissions Required, Vendor Advisory
• https://security.gentoo.org/glsa/202208-14Third Party Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-30/Vendor Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=1682370Issue Tracking, Permissions Required, Vendor Advisory
• https://security.gentoo.org/glsa/202208-14Third Party Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-30/Vendor Advisory

Published

Aug 5, 2021

Last Modified

Jun 17, 2026

Status

Modified

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