PT-2021-22924 · Crypto+++2 · Crypto+++2

Alessandro Sorniotti + 2 · Published 2021-07-01 · Updated 2024-06-15 · CVE-2021-40530

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 Crypto++ versions through 8.5

Description The ElGamal implementation in Crypto++ 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. This can lead to a cross-configuration attack against OpenPGP.

Recommendations For Crypto++ versions through 8.5, consider updating to a version that addresses this issue, as the current implementation allows for plaintext recovery. At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Use of a Broken Cryptographic Algorithm

Weakness Enumeration

CWE-327

Related Identifiers

ALT-PU-2021-2104

CVE-2021-40530

MGASA-2021-0468

OPENSUSE-SU-2024:10933-1

Affected Products

Alt Linux

Crypto++

Debian

References · 26

• 🔥 https://ibm.github.io/system-security-research-updates/2021/09/06/insecurity-elgamal-pt2 · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2021-40530 · Security Note
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HGVBZ2TTRKCTYAZTRHTF6OBD4W37F5MT · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-40530 · Vendor Advisory
• https://advisories.mageia.org/MGASA-2021-0468.html · Security Note
• https://ubuntu.com/security/CVE-2021-40530 · Vendor Advisory
• https://lists.fedoraproject.org/archives/list/[e-mail]/thread/HGVBZ2TTRKCTYAZTRHTF6OBD4W37F5MT · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-40530 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2021-40530 · Vendor Advisory
• https://osv.dev/vulnerability/openSUSE-SU-2024:10933-1 · Vendor Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/57OJA2K5AHX5HAU2QBDRWLGIIUX7GASC · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2021-40530 · Security Note
• https://osv.dev/vulnerability/MGASA-2021-0468 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2021-40530 · Vendor Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VJYOZGWI7TD27SEXILSM6VUTPPEICDL7 · Vendor Advisory