CVE-2020-1967
HIGHOpenSSL 1.1.1d-1.1.1f - Denial of Service via Invalid Signature Algorithm in TLS 1.3 Handshake
Title source: llmExploitation Summary
EIP tracks 1 public exploit for CVE-2020-1967. PoCs published by irsl.
AI-analyzed exploit summary This PoC demonstrates a DoS vulnerability in OpenSSL (CVE-2020-1967) by sending a crafted signature_algorithms_cert TLS extension during a TLS 1.3 handshake, causing a segmentation fault in vulnerable versions. The exploit requires a patched OpenSSL client and a server configured to call SSL_check_chain().
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).
Exploits (1)
This PoC demonstrates a DoS vulnerability in OpenSSL (CVE-2020-1967) by sending a crafted signature_algorithms_cert TLS extension during a TLS 1.3 handshake, causing a segmentation fault in vulnerable versions. The exploit requires a patched OpenSSL client and a server configured to call SSL_check_chain().
References (32)
Scores
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H