Vulnerability in Botan Project
CVE-2021-40529
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.
Vulnerability class: POODLE (CVE-2014-3566)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.015 (73.8th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 74th percentile — 73.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.015 · newest: 0.015 · change: 0.000
Affected products
- Botan Project
- Mozilla Thunderbird
- Fedoraproject Fedora — versions 34, 35
Weakness classification (CWE)
References
- eprint.iacr.org/2021/923 (Technical Description, Third Party Advisory)
- ibm.github.io/system-security-research-updates/2021/07/20/insecurity-elgamal-pt1 (Third Party Advisory)
- ibm.github.io/system-security-research-updates/2021/09/06/insecurity-elgamal-pt2 (Exploit, Third Party Advisory)
- github.com/randombit/botan/pull/2790 (Patch, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- security.gentoo.org/glsa/202208-14 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-40529?
- CVE-2021-40529 is a medium-severity vulnerability in Botan Project, classified under Use of a Broken or Risky Cryptographic Algorithm. CVSS score: 5.9/10. Published 2021-09-06.
- How severe is CVE-2021-40529?
- Medium severity. CVSS v3 base score is 5.9 out of 10.