CVE & CISA-KEV Catalog

CVE-2021-3449

MEDIUMEPSS 99th pctl
5.9
CVSS v3
NVD

Description

An OpenSSL TLS server may crash if sent a maliciously crafted renegotiation ClientHello message from a client. If a TLSv1.2 renegotiation ClientHello omits the signature_algorithms extension (where it was present in the initial ClientHello), but includes a signature_algorithms_cert extension then a NULL pointer dereference will result, leading to a crash and a denial of service attack. A server is only vulnerable if it has TLSv1.2 and renegotiation enabled (which is the default configuration). OpenSSL TLS clients are not impacted by this issue. All OpenSSL 1.1.1 versions are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1k. OpenSSL 1.0.2 is not impacted by this issue. Fixed in OpenSSL 1.1.1k (Affected 1.1.1-1.1.1j).

CWE-476NULL Pointer Dereference

How to fix

Remediation Available
opensslDebian
Fixed in:1.1.1k-1CVE-2021-3449
Fixed in:1.1.1k-1CVE-2021-3449
Fixed in:1.1.1k-1CVE-2021-3449
Fixed in:1.1.1k-1CVE-2021-3449
libssl1.1Ubuntu
Fixed in:1.1.1-1ubuntu2.1~18.04.9USN-4891-1
Fixed in:1.1.1f-1ubuntu2.3USN-4891-1
opensslUbuntu
Fixed in:1.1.1-1ubuntu2.1~18.04.9USN-4891-1
Fixed in:1.1.1f-1ubuntu2.3USN-4891-1
postgresql-10Ubuntu
Fixed in:10.18-0ubuntu0.18.04.1USN-5038-1
postgresql-12Ubuntu
Fixed in:12.8-0ubuntu0.20.04.1USN-5038-1
Node.jsWindows application
Affected:15.0.0 15.14.0Fixed in:15.14.0Node.js Foundation
Affected:14.15.0 14.16.1Fixed in:14.16.1Node.js Foundation
Affected:12.13.0 12.22.1Fixed in:12.22.1Node.js Foundation
Node.js (LTS)Windows application
Affected:15.0.0 15.14.0Fixed in:15.14.0Node.js Foundation
Affected:12.13.0 12.22.1Fixed in:12.22.1Node.js Foundation
Affected:14.15.0 14.16.1Fixed in:14.16.1Node.js Foundation

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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

ConfidentialityNone
IntegrityNone
AvailabilityHigh

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

Exploit Intelligence

62.91%probability of exploitation in 30 days
99thpercentile

Very high risk: more likely to be exploited than 99% of all known CVEs.

References

Vendor Advisory1

Related Vulnerabilities

Other CWE-476 (NULL Pointer Dereference) vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2023-21758High7.592%-Fix
CVE-2023-21547High7.588%-Fix
CVE-2014-3470Medium4.386%-Fix
CVE-2021-44224High8.282%-Fix
CVE-2016-0742High7.582%-Fix
CVE-2009-1386Medium5.080%-Fix
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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.