CVE-2021-40529

medium
Published — · Modified —
CVSS v3
CVSS v4 NEW
not yet in upstream
VIR risk
5.5

Description

The ElGamal implementation in Botan through 2.18.1, as used in Thunderbird and other products, allows plaintext recovery because, during interaction between two cryptographic libraries, a certain dangerous combination of the prime defined by the receiver's public key, the generator defined by the receiver's public key, and the sender's ephemeral exponents can lead to a cross-configuration attack against OpenPGP.

Predictions

Exploit likelihood
20%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

OS impact

debian Debian Mixed 3 releases
VersionStatusFixed in
trixie Fixed 2.18.1+dfsg-3
bullseye Affected
bookworm Fixed 2.18.1+dfsg-3
arch Arch Fixed 1 release
VersionStatusFixed in
Fixed 2.18.2-1

References

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.