CVE-2021-40529

medium
Published — · Modified —
CVSS v3
CVSS v2
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

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2021-40529

OS impact

OSVersionStatusFixed in
debian debianbookwormfixed2.18.1+dfsg-3
debian debianbullseyeaffected
debian debiantrixiefixed2.18.1+dfsg-3
arch archfixed2.18.2-1

References

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