CVSS 3.1
5.9 mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:NCVE-2021-40528
Medium (5.9) in gnupg libgcrypt. EPSS 1.4% chance of exploitation in the next 30 days.
The ElGamal implementation in Libgcrypt before 1.9.4 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.
Severity
- EPSS
- 1.4% chance of exploitation in the next 30 days; higher than 72% of CVEs (scores of 2026-10-31)
- CWE
- CWE-327
- Published
- Modified
- Record from
- the NVD, synced
Affected
- gnupg:libgcrypt
References
- https://eprint.iacr.org/2021/923
- https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git%3Ba=commit%3Bh=3462280f2e23e16adf3ed5176e0f2413d8861320
- https://ibm.github.io/system-security-research-updates/2021/07/20/insecurity-elgamal-pt1
- https://ibm.github.io/system-security-research-updates/2021/09/06/insecurity-elgamal-pt2
- https://security.gentoo.org/glsa/202210-13