CVE-2025-23419
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.
Does this matter?
Lower severity and a low EPSS score (2.79%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 4.0
- 5.3 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 2.79% probability · 86th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-863
- Affected
- f5/nginx · f5/nginx plus · debian/debian linux
- Source
- f5sirt@f5.com
References
- https://my.f5.com/manage/s/article/K000149173Vendor Advisory
- http://www.openwall.com/lists/oss-security/2025/02/05/8Mailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2025/03/msg00017.htmlIssue Tracking, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.