CVE-2021-40529

NameCVE-2021-40529
DescriptionThe 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.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub code/issues, web search, more)
Debian Bugs993840

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
botan (PTS)buster2.9.0-2vulnerable
bullseye2.17.3+dfsg-2vulnerable
bookworm2.19.1+dfsg-3fixed
sid2.19.2+dfsg-1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
botansource(unstable)2.18.1+dfsg-3993840
botan1.10source(unstable)(unfixed)

Notes

[bullseye] - botan <no-dsa> (Minor issue)
[buster] - botan <no-dsa> (Minor issue)
[stretch] - botan1.10 <ignored> (Affected function encrypt(...) has changed drastically. Backport is too instrusive to backport)
https://eprint.iacr.org/2021/923
https://github.com/randombit/botan/pull/2790
Fixed by: https://github.com/randombit/botan/commit/9a23e4e3bc3966340531f2ff608fa9d33b5185a2
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

Search for package or bug name: Reporting problems