CVE-2020-1967

Segmentation fault in SSL_check_chain

HIGH
7.5
CVSS Score
Published: April 21, 2020 at 01:45 PM UTC
Updated: October 8, 2026 at 09:17 PM UTC
26 products affected across 10 vendorsDebian LinuxFedoraLeap

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Severity
HIGH7.5
Exploit prediction
EPSS 53%
SSVC
No known exploit

Description

Server or client applications that call the SSL_check_chain() function during or after a TLS 1.3 handshake may crash due to a NULL pointer dereference as a result of incorrect handling of the "signature_algorithms_cert" TLS extension. The crash occurs if an invalid or unrecognised signature algorithm is received from the peer. This could be exploited by a malicious peer in a Denial of Service attack. OpenSSL version 1.1.1d, 1.1.1e, and 1.1.1f are affected by this issue. This issue did not affect OpenSSL versions prior to 1.1.1d. Fixed in OpenSSL 1.1.1g (Affected 1.1.1d-1.1.1f).

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

References (32)

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-476

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