CVE & CISA-KEV Catalog

CVE-2021-20305

HIGHEPSS 73th pctl
8.1
CVSS v3
NVD

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.

CWE-327CWE-787Out-of-bounds Write

How to fix

Remediation Available
nettleDebian
Fixed in:3.7.2-1CVE-2021-20305
Fixed in:3.7.2-1CVE-2021-20305
Fixed in:3.7.2-1CVE-2021-20305
Fixed in:3.7.2-1CVE-2021-20305
libnettle6Ubuntu
Fixed in:3.2-1ubuntu0.16.04.2USN-4906-1
Fixed in:3.4-1ubuntu0.1USN-4906-1
libnettle7Ubuntu
Fixed in:3.5.1+really3.5.1-2ubuntu0.1USN-4906-1
nettleUbuntu
Fixed in:3.2-1ubuntu0.16.04.2USN-4906-1
Fixed in:3.4-1ubuntu0.1USN-4906-1
Fixed in:3.5.1+really3.5.1-2ubuntu0.1USN-4906-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredNone
User InteractionNone
ScopeUnchanged

Impact

ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

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

Exploit Intelligence

1.61%probability of exploitation in 30 days
73rdpercentile

Elevated risk: more likely to be exploited than 73% of all known CVEs.

References

Other references1
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Markdown

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.