Vulnerability in Mozilla Thunderbird

CVE-2021-29949

When loading the shared library that provides the OTR protocol implementation, Thunderbird will initially attempt to open it using a filename that isn't distributed by Thunderbird. If a computer has already been infected with a malicious library of the alternative filename, and the malicious library has been copied to a directory that is contained in the search path for executable libraries, then Thunderbird will load the incorrect library. This vulnerability affects Thunderbird < 78.9.1.

EPSS: 0.003 (23.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-29949?
CVE-2021-29949 is a high-severity vulnerability in Mozilla Thunderbird, classified under Uncontrolled Search Path Element. CVSS score: 7.8/10. Published 2021-06-24.
How severe is CVE-2021-29949?
High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2021-29949 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.