// For flags

CVE-2025-23419

TLS Session Resumption Vulnerability

Severity Score

5.3
*CVSS v4

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

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.

It was discovered that nginx incorrectly handled when multiple server blocks are configured to share the same IP address and port. An attacker could use this issue to use session resumption to bypass client certificate authentication requirements on these servers. This issue only affected Ubuntu 24.10. A buffer overflow and a null pointer deref was fixed in nginx rtmp module. This issue only affected Ubuntu 20.04 LTS and Ubuntu 22.04 LTS.

*Credits: Sven Hebrok, Felix Cramer, Tim Storm, Maximilian Radoy, Juraj Somorovsky
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
Low
User Interaction
None
System
Vulnerable | Subsequent
Confidentiality
Low
None
Integrity
None
None
Availability
None
None
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None
Attack Vector
Network
Attack Complexity
Low
Authentication
Single
Confidentiality
Partial
Integrity
None
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2025-01-22 CVE Reserved
  • 2025-02-05 CVE Published
  • 2025-02-12 CVE Updated
  • 2025-04-01 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-287: Improper Authentication
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
F5
Search vendor "F5"
 NGINX Open Source
Search vendor "F5" for product "NGINX Open Source"
 < 1.11.4
Search vendor "F5" for product "NGINX Open Source" and version " < 1.11.4"
en
Affected