Privilege escalation in Mozilla Thunderbird

CVE-2021-43528

Thunderbird unexpectedly enabled JavaScript in the composition area. The JavaScript execution context was limited to this area and did not receive chrome-level privileges, but could be used as a stepping stone to further an attack with other vulnerabilities. This vulnerability affects Thunderbird < 91.4.0.

Vulnerability class: Privilege Escalation

EPSS: 0.013 (66.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-43528?
CVE-2021-43528 is a medium-severity vulnerability in Mozilla Thunderbird, classified under Improper Privilege Management. CVSS score: 6.5/10. Published 2021-12-08.
How severe is CVE-2021-43528?
Medium severity. CVSS v3 base score is 6.5 out of 10.