| Name | CVE-2021-40530 |
| Description | The ElGamal implementation in Crypto++ through 8.5 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. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| Debian Bugs | 993841 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| libcrypto++ (PTS) | jessie, jessie (lts) | 5.6.1-6+deb8u3 | vulnerable |
| stretch | 5.6.4-7 | vulnerable | |
| buster | 5.6.4-8 | vulnerable | |
| bullseye | 8.4.0-1 | vulnerable | |
| bookworm | 8.7.0+git220824-1 | fixed | |
| sid, trixie | 8.9.0-1.1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| libcrypto++ | source | jessie | (unfixed) | end-of-life | ||
| libcrypto++ | source | (unstable) | 8.6.0-1 | 993841 |
[bullseye] - libcrypto++ <no-dsa> (Minor issue)
[buster] - libcrypto++ <no-dsa> (Minor issue)
[stretch] - libcrypto++ <no-dsa> (Minor issue)
https://eprint.iacr.org/2021/923
https://github.com/weidai11/cryptopp/issues/1059
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://github.com/weidai11/cryptopp/commit/bee8e8ca6658 (CRYPTOPP_8_6_0)