Medium severity6.5NVD Advisory· Published Jun 24, 2021· Updated Jun 17, 2026
CVE-2021-23993
CVE-2021-23993
Description
An attacker may perform a DoS attack to prevent a user from sending encrypted email to a correspondent. If an attacker creates a crafted OpenPGP key with a subkey that has an invalid self signature, and the Thunderbird user imports the crafted key, then Thunderbird may try to use the invalid subkey, but the RNP library rejects it from being used, causing encryption to fail. This vulnerability affects Thunderbird < 78.9.1.
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Affected products
5cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*+ 2 more
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*range: <78.9.1
- (no CPE)range: <78.9.1
- (no CPE)range: unspecified
- osv-coords2 versionspkg:rpm/opensuse/MozillaThunderbird&distro=openSUSE%20Leap%2015.2pkg:rpm/opensuse/MozillaThunderbird&distro=openSUSE%20Tumbleweed
< 78.9.1-lp152.2.38.1+ 1 more
- (no CPE)range: < 78.9.1-lp152.2.38.1
- (no CPE)range: < 91.1.1-1.1
Patches
Vulnerability mechanics
References
2- bugzilla.mozilla.org/show_bug.cginvdIssue TrackingPermissions RequiredVendor Advisory
- www.mozilla.org/security/advisories/mfsa2021-13/nvdRelease NotesVendor Advisory
News mentions
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