#VU46295 NULL pointer dereference in GnuTLS - CVE-2020-24659
Published: September 4, 2020 / Updated: September 6, 2020
Vulnerability identifier: #VU46295
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2020-24659
CWE-ID: CWE-476
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
GnuTLS
GnuTLS
Software vendor:
GnuTLS
GnuTLS
Description
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error in GnuTLS before 3.6.15. A server can trigger a NULL pointer dereference in a TLS 1.3 client if a no_renegotiation alert is sent with unexpected timing, and then an invalid second handshake occurs. The crash happens in the application's error handling path, where the gnutls_deinit function is called after detecting a handshake failure. A remote attacker can perform a denial of service (DoS) attack.
Remediation
Update to version 3.6.15.