CVE-2024-38475
Apache HTTP Server Improper Escaping of Output
- Published1 Jul 2024
- Added to CISA KEV1 May 2025
- Remediation due22 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.
CVSS 3.1 breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NAffected products
Remediation
References
- https://github.com/apache/httpd/commit/9a6157d1e2f7ab15963020381054b48782bc18cf
- https://httpd.apache.org/security/vulnerabilities_24.html
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2024-0018
- https://security.netapp.com/advisory/ntap-20240712-0001/
- https://www.blackhat.com/us-24/briefings/schedule/index.html#confusion-attacks-exploiting-hidden-semantic-ambiguity-in-apache-http-server-pre-recorded-40227
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-38475
- http://www.openwall.com/lists/oss-security/2024/07/01/8
Related CVEs
Recent high-severity vulnerabilities sharing a weakness type.
Frequently asked
Is CVE-2024-38475 being actively exploited?
Yes. CVE-2024-38475 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 1 May 2025.
How severe is CVE-2024-38475?
CVE-2024-38475 has a CVSS 3.1 base score of 9.1, rated critical. EPSS estimates a 100.0% probability of exploitation.
Which products are affected by CVE-2024-38475?
Affected products include Apache HTTP Server, Netapp Ontap 9, SonicWall Sma 200 Firmware, SonicWall Sma 210 Firmware, SonicWall Sma 400 Firmware, and 2 more.
How do I fix CVE-2024-38475?
Upgrade affected software to a fixed version, for example Apache HTTP Server 2.4.60, SonicWall Sma 200 Firmware 10.2.1.14-75sv, SonicWall Sma 210 Firmware 10.2.1.14-75sv or later, then confirm no affected versions remain in your inventory.
How Secuno handles this
Secuno correlates vulnerabilities like CVE-2024-38475 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, a risk for it never ranks below high, and the update that fixes it moves to the Emergency patch lane. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.
Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.