HIGH

CVE-2020-1967

CVSS v3

7.5

HIGH

EPSS Score

64.7%

exploit probability

CISA KEV

No

known exploited

Exploitation

SSVC status

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).

Technical details

Published
4/21/2020

Frequently asked questions

What is CVE-2020-1967?

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).

Is CVE-2020-1967 actively exploited?

Active exploitation of CVE-2020-1967 has not been confirmed. The EPSS score is 64.7%, indicating the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-1967?

CVE-2020-1967 has a CVSS v3 base score of 7.5 (HIGH severity).

Is CVE-2020-1967 affecting your environment?

Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.