CVE-2021-29969: mozilla thunderbird
Vulnerability summary
CVE-2021-29969 is a medium (CVSS 5.9) vulnerability in mozilla thunderbird. EPSS estimates a 1.20% chance of exploitation in the next 30 days, higher than 67.7% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 12 · Related 5Timeline
- 05-08-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
4 scores · 3 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · DebianEcosystem advisory · calculated5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS trend
Probability
1.20%
Chance of exploitation in the next 30 days
Percentile
68%
Versus all other CVEs
30-day change
0.00 pp
From 1.20% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Debian1 product
- thunderbird< 1:78.12.0-1
Mozilla1 product
- thunderbird≥ unspecified, < 78.12 | < 78.12
Ubuntu1 product
- thunderbird< 1:78.13.0+build1-0ubuntu0.18.04.1 | < 1:78.13.0+build1-0ubuntu0.20.04.2
3 vendors · 3 products
References
8 links- bugzilla.mozilla.org/show_bug.cgi?id=1682370X Refsource MISCIssue TrackingPermissions RequiredVendor Advisory
