SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

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.

HIGH 7.5EPSS 53.3%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 53.3%, higher than 99% of all known CVEs. Patch or mitigate before the next change window.

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).

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
53.34% probability · 99th percentile
CISA KEV
Not listed
Weakness
CWE-476
Affected
openssl/openssl · debian/debian linux · freebsd/freebsd · fedoraproject/fedora · oracle/application server · oracle/enterprise manager base platform · oracle/enterprise manager for storage management · oracle/enterprise manager ops center · oracle/http server · oracle/jd edwards world security · oracle/mysql · oracle/mysql connectors · oracle/mysql enterprise monitor · oracle/mysql workbench · oracle/peoplesoft enterprise peopletools · netapp/active iq unified manager · netapp/e-series performance analyzer · netapp/oncommand insight · netapp/oncommand workflow automation · netapp/smi-s provider · +6 more
Source
openssl-security@openssl.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.