CVE-2021-20305

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.

References


Issue TrackingPatchThird Party Advisory

CvssV3 impact


BaseSeverity

CRITICAL

ConfidentialityImpact

HIGH

AttackComplexity

LOW

Scope

UNCHANGED

AttackVector

NETWORK

AvailabilityImpact

HIGH

IntegrityImpact

HIGH

PrivilegesRequired

NONE

BaseScore

9.8

VectorString

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

Version

3.1

UserInteraction

NONE

CvssV2 impact


AccessComplexity

LOW

ConfidentialityImpact

PARTIAL

AvailabilityImpact

PARTIAL

IntegrityImpact

PARTIAL

BaseScore

7.5

VectorString

AV:N/AC:L/Au:N/C:P/I:P/A:P

Version

2.0

AccessVector

NETWORK

Authentication

NONE