CVE-2020-1967: Segmentation fault in SSL_check_chain
Server or client applications that call the SSLcheckchain() 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 "signaturealgorithmscert" 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 Software
Remediation
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Event History
Frequently Asked Questions
What is the vulnerability ID for this issue?
The vulnerability ID for this issue is CVE-2020-1967.
How severe is CVE-2020-1967?
CVE-2020-1967 has a severity rating of 7.5 (High).
Which applications are affected by CVE-2020-1967?
Server or client applications that call the SSL_check_chain() function during or after a TLS 1.3 handshake are affected.
What is the impact of CVE-2020-1967?
The impact of CVE-2020-1967 is a crash of the application due to a NULL pointer dereference.
How can I fix CVE-2020-1967?
To fix CVE-2020-1967, update to the recommended versions of OpenSSL or apply the provided patches.