Background exploitation KEV catalog No authentication
CVE-2024-38475

Apache HTTP Server Improper Escaping of Output Vulnerability

Improper escaping of output in mod_rewrite in Apache HTTP Server 2.4.59 and earlier allows an attacker to map URLs to filesystem locations that are permitted to be served by the server but are not intentionally/directly reachable by any…

CheckOps priority index
9.0/10 Patch within 24 h
Severity9.1
Probability10.0
Exploitation4/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 99.96% higher than 99.98% of CVEs
CVSS 3.1 9.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:
Exploited for 551 days 01 May 2025
CISA due date 22 May 2025 for US federal agencies

Exploitation probability EPSS · FIRST

05010025 Sep05 Oct15 Oct24 Oct02 Nov
EPSS probability (%)Percentile among all CVEs

Exploitation signals 4 / 5

  • KEV catalog (CISA)01 May 2025
  • Exploited in EUVD (ENISA)01 May 2025
  • Used by ransomwareno
  • EPSS above 10 %99.96%
  • No account, over the networkyes

What to do

Fix

Update to a fixed version: 2.4.60-1

CISA guidance: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

Improper escaping of output in mod_rewrite in Apache HTTP Server 2.4.59 and earlier allows an attacker to map URLs to filesystem locations that are permitted to be served by the server but are not intentionally/directly reachable by any URL, resulting in code execution or source code disclosure. Substitutions in server context that use a backreferences or variables as the first segment of the substitution are affected.  Some unsafe RewiteRules will be broken by this change and the rewrite flag "UnsafePrefixStat" can be used to opt back in once ensuring the substitution is appropriately constrained.

Affected products

Apache HTTP ServerHTTP Server
Affected versions
  • 2.4.0 ≤2.4.59
Weaknesses (CWE)

Open source packages OSV

  • apache2Debian:13 · CVE-2024-38475
    fixed in 2.4.60-1

Timeline

  1. Published

  2. Exploitation reported (ENISA)

  3. Added to the KEV catalog

  4. CISA remediation due date

  5. EPSS peak: 99.96%

References

Other exploited vulnerabilities from the same vendor

  • CVE-2016-3081Apache Struts Command Injection Vulnerability
    8.5 · Rising fast
  • CVE-2026-34486Apache Tomcat Missing Encryption of Sensitive Data Vulnerability
    8.4 · Actively exploited
  • CVE-2026-34197Apache ActiveMQ Improper Input Validation Vulnerability
    8.3 · Background exploitation
  • CVE-2025-24813Apache Tomcat Path Equivalence Vulnerability
    9.4 · Background exploitation
  • CVE-2024-45195Apache OFBiz Forced Browsing Vulnerability
    9.3 · Background exploitation
  • CVE-2024-27348Apache HugeGraph-Server Improper Access Control Vulnerability
    9.3 · Background exploitation

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Sources: CISA KEV · ENISA EUVD · FIRST EPSS · OSV. Public data aggregated by CheckOps, updated automatically. Source texts remain the property of their authors. All exploited vulnerabilities