Vulnerability in Mozilla Thunderbird

CVE-2018-18509

A flaw during verification of certain S/MIME signatures causes emails to be shown in Thunderbird as having a valid digital signature, even if the shown message contents aren't covered by the signature. The flaw allows an attacker to reuse a valid S/MIME signature to craft an email message with arbitrary content. This vulnerability affects Thunderbird < 60.5.1.

EPSS: 0.017 (74.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2018-18509?
CVE-2018-18509 is a medium-severity vulnerability in Mozilla Thunderbird, classified under Improper Verification of Cryptographic Signature. CVSS score: 5.3/10. Published 2019-04-26.
How severe is CVE-2018-18509?
Medium severity. CVSS v3 base score is 5.3 out of 10.