PT-2021-22923 · Botan+4 · Botan+4

Alessandro Sorniotti + 2 · Published 2021-09-06 · Updated 2024-06-15 · CVE-2021-40529

Positive Technologies (AI Summary)

CVSS v3.1

5.9

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions Botan versions through 2.18.1

Description The issue allows plaintext recovery due to a certain 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, leading to a cross-configuration attack against OpenPGP.

Recommendations For Botan versions through 2.18.1, update to a version later than 2.18.1 to resolve the issue. As a temporary workaround, consider restricting the use of the ElGamal implementation until a patch is available.

Exploit

Fix

Use of a Broken Cryptographic Algorithm

Weakness Enumeration

CWE-327

Related Identifiers

ALT-PU-2022-1663

ALT-PU-2022-2515

ALT-PU-2022-2890

ALT-PU-2022-2931

ALT-PU-2023-1137

ALT-PU-2023-4335

CVE-2021-40529

MGASA-2021-0563

OPENSUSE-SU-2021:1635-1

OPENSUSE-SU-2021:4150-1

OPENSUSE-SU-2021_1635-1

OPENSUSE-SU-2021_4150-1

OPENSUSE-SU-2024:11661-1

OPENSUSE-SU-2024:11670-1

SUSE-SU-2021:4150-1

Affected Products

Alt Linux

Botan

Debian

Openpgp

Suse

References · 69

• 🔥 https://ibm.github.io/system-security-research-updates/2021/09/06/insecurity-elgamal-pt2 · Exploit
• https://github.com/randombit/botan/pull/2790 · Patch
• https://security-tracker.debian.org/tracker/CVE-2021-40529 · Vendor Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/72NB4OLD3VHJC3YF3PEP2HKF6BYURPAO · Vendor Advisory
• https://osv.dev/vulnerability/ALPINE-CVE-2021-40529 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-40529 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-40529 · Security Note
• https://osv.dev/vulnerability/SUSE-SU-2021:4150-1 · Vendor Advisory
• https://advisories.mageia.org/MGASA-2021-0563.html · Security Note
• https://cve.org/CVERecord?id=CVE-2021-40529 · Security Note
• https://osv.dev/vulnerability/MGASA-2021-0563 · Vendor Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UPHGYWNJQKWLTUWBNSFB4F66MQDIL3IB · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-40529 · Vendor Advisory
• https://osv.dev/vulnerability/openSUSE-SU-2024:11661-1 · Vendor Advisory
• https://osv.dev/vulnerability/openSUSE-SU-2021:1635-1 · Vendor Advisory