CVE-2025-23419: TLS Session Resumption Vulnerability
Description
When multiple server blocks are configured to share the same IP address and port, an attacker can use session resumption to bypass client certificate authentication requirements on these servers. This vulnerability arises when TLS Session Tickets https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_ticket_key are used and/or the SSL session cache https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_cache are used in the default server and the default server is performing client certificate authentication.
Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Classification
CVE ID: CVE-2025-23419
CVSS Base Severity: MEDIUM
CVSS Base Score: 4.3
CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Affected Products
Vendor: F5
Product: NGINX Open Source
Exploit Prediction Scoring System (EPSS)
EPSS Score: 0.04% (probability of being exploited)
EPSS Percentile: 11.85% (scored less or equal to compared to others)
EPSS Date: 2025-03-06 (when was this score calculated)