Vulnerability · Published Jan 10, 2025 · Assigned by mitre
CVE-2025-23016
Critical 9.3
In plain English
A critical-severity integer overflow in fcgi from FastCGI. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 50% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)9.3Critical
Exploit odds (30 days)0.6%top 50.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
FastCGI fcgi2 (aka fcgi) 2.x through 2.4.4 has an integer overflow (and resultant heap-based buffer overflow) via crafted nameLen or valueLen values in data to the IPC socket. This occurs in ReadParams in fcgiapp.c.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libfcgi | 2.4.2-2+deb12u1 | DEBIAN-CVE-2025-23016 |
| Debian:13 | libfcgi | 2.4.5-0.1 | DEBIAN-CVE-2025-23016 |
| Debian:14 | libfcgi | 2.4.5-0.1 | DEBIAN-CVE-2025-23016 |
| Ubuntu:22.04:LTS | libfcgi | 2.4.2-2ubuntu0.1 | USN-7486-1 |
| Ubuntu:22.04:LTS | libfcgi | 2.4.2-2ubuntu0.1 | UBUNTU-CVE-2025-23016 |
| Ubuntu:24.04:LTS | libfcgi | 2.4.2-2.1ubuntu0.24.04.1 | UBUNTU-CVE-2025-23016 |
| Ubuntu:24.04:LTS | libfcgi | 2.4.2-2.1ubuntu0.24.04.1 | USN-7486-1 |
| Ubuntu:25.10 | libfcgi | 2.4.5-0.1 | UBUNTU-CVE-2025-23016 |
Affected products (as reported)
Weakness: CWE-190 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
References
- https://github.com/FastCGI-Archives/fcgi2/issues/67
- https://github.com/FastCGI-Archives/fcgi2/releases/tag/2.4.5
- https://www.synacktiv.com/en/publications/cve-2025-23016-exploiting-the-fastcgi-library
- http://www.openwall.com/lists/oss-security/2025/04/23/4
- https://lists.debian.org/debian-lts-announce/2025/10/msg00009.html