CVE-2021-29969

low-risk

Published 2021-08-05

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.

Do I need to act?

0.40% chance of exploitation

EPSS score — low exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 5.9/10 Medium

NETWORK / HIGH complexity

Affected Products (1)

Thunderbird

Affected Vendors

Mozilla

References (6)

Issue Tracking https://bugzilla.mozilla.org/show_bug.cgi?id=1682370

Third Party Advisory https://security.gentoo.org/glsa/202208-14

Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2021-30/

Issue Tracking https://bugzilla.mozilla.org/show_bug.cgi?id=1682370

Third Party Advisory https://security.gentoo.org/glsa/202208-14

Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2021-30/

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low-risk

Severity 18/34 · Moderate

Exploitability 2/34 · Minimal

Exposure 5/34 · Minimal