Improper Output Neutralization for Logs Affecting cpp-httplib package, versions <0.41.0+ds-3


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.27% (19th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-DEBIANUNSTABLE-CPPHTTPLIB-14193181
  • published6 Dec 2025
  • disclosed5 Dec 2025

Introduced: 5 Dec 2025

CVE-2025-66577  (opens in a new tab)
CWE-117  (opens in a new tab)
CWE-807  (opens in a new tab)

How to fix?

Upgrade Debian:unstable cpp-httplib to version 0.41.0+ds-3 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream cpp-httplib package and not the cpp-httplib package as distributed by Debian. See How to fix? for Debian:unstable relevant fixed versions and status.

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.27.0, a vulnerability allows attacker-controlled HTTP headers to influence server-visible metadata, logging, and authorization decisions. An attacker can supply X-Forwarded-For or X-Real-IP headers which get accepted unconditionally by get_client_ip() in docker/main.cc, causing access and error logs (nginx_access_logger / nginx_error_logger) to record spoofed client IPs (log poisoning / audit evasion). This vulnerability is fixed in 0.27.0.

CVSS Base Scores

version 3.1