⚠ Known Exploited Vulnerability (KEV) Tracker

Description

Some mod_proxy configurations on Apache HTTP Server versions 2.4.0 through 2.4.55 allow a HTTP Request Smuggling attack. Configurations are affected when mod_proxy is enabled along with some form of RewriteRule or ProxyPassMatch in which a non-specific pattern matches some portion of the user-supplied request-target (URL) data and is then re-inserted into the proxied request-target using variable substitution. For example, something like: RewriteEngine on RewriteRule "^/here/(.*)" "http://example.com:8080/elsewhere?$1"; [P] ProxyPassReverse /here/ http://example.com:8080/ Request splitting/smuggling could result in bypass of access controls in the proxy server, proxying unintended URLs to existing origin servers, and cache poisoning. Users are recommended to update to at least version 2.4.56 of Apache HTTP Server.

Lifecycle Timeline

• 2023-03-07
  CVE published

  Entered the public CVE record.

  CVE.org →
• 2023-04-25
  Public exploit code 49 days later

  Public GitHub repository tbachvarova/linux-apache-fix-mod_rewrite-spaceInURL — unvetted, may contain malware

  GitHub PoC →
• 2024-07-25
  First national advisory 15 months later

  NSA — North Korea Cyber Group Conducts Global Espionage Campaign to Advance Regime’s Military and Nuclear Programs

  CyberzSOC advisory index →
• not recorded
  EPSS flags exploitation risk

  Reached 10% only through a model recalibration, which moves every score at once and says nothing about this CVE.
• not recorded
  Added to CISA KEV

  Not in the CISA KEV catalog.
• not recorded
  Federal remediation due

  No remediation deadline set.
• not recorded
  Vendor fix published

  No dated vendor fix. Only Microsoft publishes a machine-readable release date; other vendors state a fixed version without one.

Each milestone comes from a different source, so gaps between them are gaps in what those sources publish, not evidence that nothing happened. EPSS history for this CVE holds 197 points from 2023-03-11, tracked daily from 2026-09-09; earlier points are weekly, which dates a spike to within a week. Peak probability 90.0% on 2025-03-22.

Published Applicability

Check whether a specific version is affected →

What each source publishes about which product versions carry this vulnerability, kept as written rather than merged. Absence here means no source has published applicability data, not that nothing is affected.

Research & News Coverage

No mentions found in monitored research blogs or news feeds.

Detection & Exploitation

Coverage across public collections only: Nuclei and OpenVAS NVT (scan); Snort and Suricata ET Open (network); Sigma and YARA (host/SIEM); Metasploit, Exploit-DB and public GitHub repositories (exploit). Absence here means nothing public was found, not that detection is impossible.
GitHub PoC repositories are collected automatically by PoC-in-GitHub (CC0) and are not vetted: some are fakes and some are malware. Treat them as evidence that code was published, not as code to run.
OpenVAS coverage derives from the Greenbone Community Feed, made available under the Open Database License (ODbL) v1.0; its individual Vulnerability Tests are licensed GNU GPL v2.

Distribution Status

Where the distribution has shipped a fix, and in which version. Green means the release has resolved it, amber that it is still open. Data from the Debian Security Tracker, used under Debian's MIT / GPLv2+ terms. Debian is upstream of several other distributions, so a fix here often precedes theirs.

CISA Assessment (Vulnrichment / SSVC)

Listed By

Referenced in Advisories

Weaponization Timeline — Offensive & Testing Tools

No exploit-tool sightings recorded for this CVE.

Evidence tiers are explained on the About page — a merged Metasploit module is far stronger evidence than a distro package mention.

External References

CVE.org record → NVD entry → FortiGuard Labs → Rapid7 AttackerKB →