CVE-2024-38475
Apache HTTP Server Improper Escaping of Output Vulnerability
IN CISA KEV
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.
- Vendor
- Apache
- Product
- HTTP Server
- CVSS 3.1
- 9.1 (critical), scored by NVD (primary)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- CVSS 3.1
- 9.1 (critical), scored by 134c704f-9b21-4f2e-91b3-4a467353bcc0CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- CWE
- CWE-116
- Published
- 2024-07-01
- NVD modified
- 2026-06-17
- NVD status
- Analyzed
CISA KEV
- Date added
- 2025-05-01
- Due date
- 2025-05-22
- Ransomware use
- Unknown
- Required action
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
EPSS
100% chance of exploitation in the next 30 days (percentile 99th)
FIRST EPSS, updated 17 Oct 2026. About EPSS
CVSS is severity, EPSS is likelihood, KEV means already exploited. EPSS is a statistical probability, not a certainty: a low score does not make a bug safe, and a high one does not prove it is being exploited.
References
- httpd.apache.org (Vendor Advisory)
- security.netapp.com (Third Party Advisory)
- www.openwall.com (Third Party Advisory)
- github.com (Patch)
- httpd.apache.org (Vendor Advisory)
- psirt.global.sonicwall.com (Third Party Advisory)
- security.netapp.com (Third Party Advisory)
- www.blackhat.com (Third Party Advisory)
- www.cisa.gov (Third Party Advisory, US Government Resource)
Data last updated 18 Oct 2026. Sources: NVD API 2.0, CISA KEV catalog, FIRST EPSS. Links: NVD, CISA KEV. Metadata only. ThreatWire does not host exploit code.