CVE-2024-38475
Apache HTTP Server weakness in mod_rewrite when first segment of substitution matches filesystem path.
- Critical 9.1
- Exploited: added to CISA KEV 1 May 2025
Description
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.
Key facts
- Published
- 1 Jul 2024
- Last changed
- 3 Nov 2025
- Assigned by
- apache
- KEV added
- 1 May 2025
- KEV fix due
- 22 May 2025
- EPSS
- 99.957% likely to be exploited in the next 30 days, higher than 99.975% of CVEs (scores for 15 Nov 2026)
- SSVC (CISA)
- Exploitation: active; Automatable: yes; Technical impact: total
Severity scores
Each score is shown as its source gave it. They are not averaged or merged.
- 9.1CVSS 3.1, Criticalfrom CISA (ADP container)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
What to do
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.CISA KEV required action
Historical context and remediation
This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.
No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.
Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.
Affected products
| Vendor | Product | Versions |
|---|---|---|
| Apache Software Foundation | Apache HTTP Server |
|
Timeline
- 1 Apr 2024 reported
- 1 Jul 2024 Published
- 1 May 2025 CVE-2024-38475 added to CISA KEV
- 1 May 2025 Added to the CISA KEV catalogue