CVE-2021-40529

medium

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.

References

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/randombit/botan/pull/2790

https://eprint.iacr.org/2021/923

https://lists.fedoraproject.org/archives/list/[email protected]/message/UPHGYWNJQKWLTUWBNSFB4F66MQDIL3IB/

https://lists.fedoraproject.org/archives/list/[email protected]/message/72NB4OLD3VHJC3YF3PEP2HKF6BYURPAO/

https://security.gentoo.org/glsa/202208-14

Details

Source: MITRE

Published: 2021-09-06

Updated: 2022-12-09

Type: CWE-327

Risk Information

CVSS v2

Base Score: 2.6

Vector: AV:N/AC:H/Au:N/C:P/I:N/A:N

Impact Score: 2.9

Exploitability Score: 4.9

Severity: LOW

CVSS v3

Base Score: 5.9

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Impact Score: 3.6

Exploitability Score: 2.2

Severity: MEDIUM