CVE-2020-1967

Name of the Vulnerable Software and Affected Versions OpenSSL versions 1.1.1d through 1.1.1f MySQL Server versions 5.6.48 and earlier, 5.7.30 and earlier, 8.0.20 and earlier

Description The issue is related to the incorrect handling of the "signature algorithms cert" TLS extension, which can cause a NULL pointer dereference and lead to a crash during or after a TLS 1.3 handshake. This could be exploited by a malicious peer in a Denial of Service attack. The crash occurs if an invalid or unrecognised signature algorithm is received from the peer.

Recommendations For OpenSSL versions 1.1.1d through 1.1.1f, update to OpenSSL 1.1.1g to fix the issue. For MySQL Server versions 5.6.48 and earlier, 5.7.30 and earlier, 8.0.20 and earlier, update to a version that includes the fix for this issue. As a temporary workaround, consider disabling the SSL check chain() function until a patch is available. Restrict access to the vulnerable module to minimize the risk of exploitation. Avoid using the signature algorithms cert TLS extension in the affected API endpoint until the issue is resolved.