CVE-2021-20305 Information

Description

A flaw was found in Nettle in versions before 3.7.2 where several Nettle signature verification functions (GOST DSA EDDSA & ECDSA) result in the Elliptic Curve Cryptography point (ECC) multiply function being called with out-of-range scalers possibly resulting in incorrect results. This flaw allows an attacker to force an invalid signature causing an assertion failure or possible validation. The highest threat to this vulnerability is to confidentiality integrity as well as system availability.

CVSS Vector

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

Reference

https://bugzilla.redhat.com/show_bug.cgi?id=1942533 https://security.gentoo.org/glsa/202105-31 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MQKWVVMAIDAJ7YAA3VVO32BHLDOH2E63/ https://www.debian.org/security/2021/dsa-4933 https://lists.debian.org/debian-lts-announce/2021/09/msg00008.html https://security.netapp.com/advisory/ntap-20211022-0002/

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

8.1