CVE-2024-38475

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.

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.

Apache HTTP Server is a powerful and flexible HTTP/1.1 compliant web server.

Security Fix(es):

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.(CVE-2024-38475)

Potential SSRF in mod_rewrite in Apache HTTP Server 2.4.59 and earlier allows an attacker to cause unsafe RewriteRules to unexpectedly setup URL's to be handled by mod_proxy. Users are recommended to upgrade to version 2.4.60, which fixes this issue.(CVE-2024-39573)

The httpd packages provide the Apache HTTP Server, a powerful, efficient, and extensible web server.

Security Fix(es):

• httpd: Encoding problem in mod_proxy (CVE-2024-38473)

• httpd: Substitution encoding issue in mod_rewrite (CVE-2024-38474)

• httpd: Improper escaping of output in mod_rewrite (CVE-2024-38475)

• httpd: NULL pointer dereference in mod_proxy (CVE-2024-38477)

• httpd: Potential SSRF in mod_rewrite (CVE-2024-39573)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

The httpd packages provide the Apache HTTP Server, a powerful, efficient, and extensible web server.

Security Fix(es):

• httpd: Improper escaping of output in mod_rewrite (CVE-2024-38475)

• httpd: Substitution encoding issue in mod_rewrite (CVE-2024-38474)

• httpd: null pointer dereference in mod_proxy (CVE-2024-38477)

• httpd: Potential SSRF in mod_rewrite (CVE-2024-39573)

• httpd: Encoding problem in mod_proxy (CVE-2024-38473)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

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.

The httpd packages provide the Apache HTTP Server, a powerful, efficient, and extensible web server.

Security Fix(es):

• httpd: Encoding problem in mod_proxy (CVE-2024-38473)
• httpd: Substitution encoding issue in mod_rewrite (CVE-2024-38474)
• httpd: Improper escaping of output in mod_rewrite (CVE-2024-38475)
• httpd: NULL pointer dereference in mod_proxy (CVE-2024-38477)
• httpd: Potential SSRF in mod_rewrite (CVE-2024-39573)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

The httpd packages provide the Apache HTTP Server, a powerful, efficient, and extensible web server.

Security Fix(es):

• httpd: Improper escaping of output in mod_rewrite (CVE-2024-38475)
• httpd: Substitution encoding issue in mod_rewrite (CVE-2024-38474)
• httpd: null pointer dereference in mod_proxy (CVE-2024-38477)
• httpd: Potential SSRF in mod_rewrite (CVE-2024-39573)
• httpd: Encoding problem in mod_proxy (CVE-2024-38473)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

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.

• CVE-2024-38474: mod_rewrite: server weakness with encoded question marks in backreferences
• CVE-2024-38475: mod_rewrite: server weakness in mod_rewrite when first segment of substitution matches filesystem path
• CVE-2024-38477: mod_proxy: crash resulting in Denial of Service in mod_proxy via a malicious request
• CVE-2024-38476: http: server use exploitable/malicious backend application output to run local handlers via internal redirect
• CVE-2024-39573: mod_rewrite: proxy handler substitution

• CVE-2024-38474: mod_rewrite: server weakness with encoded question marks in backreferences
• CVE-2024-38475: mod_rewrite: server weakness in mod_rewrite when first segment of substitution matches filesystem path
• CVE-2024-38477: mod_proxy: crash resulting in Denial of Service in mod_proxy via a malicious request
• CVE-2023-38709: http_filters: HTTP response splitting
• CVE-2024-38473: mod_proxy: server proxy encoding problem
• CVE-2024-39573: mod_rewrite: proxy handler substitution
• CVE-2024-38476: http: server use exploitable/malicious backend application output to run local handlers via internal redirect
• CVE-2024-39884: modules: source code disclosure with handlers configured via AddType. Resolving regression introduced by CVE-2024-38476 fix
• CVE-2024-40725: modules: source code disclosure with handlers configured via AddType. Resolving regression introduced by CVE-2024-39884 fix

• CVE-2024-38474: mod_rewrite: server weakness with encoded question marks in backreferences
• CVE-2024-38475: mod_rewrite: server weakness in mod_rewrite when first segment of substitution matches filesystem path
• CVE-2024-38477: mod_proxy: crash resulting in Denial of Service in mod_proxy via a malicious request
• CVE-2023-38709: http_filters: HTTP response splitting
• CVE-2024-38473: mod_proxy: server proxy encoding problem
• CVE-2024-39573: mod_rewrite: proxy handler substitution
• CVE-2024-38476: http: server use exploitable/malicious backend application output to run local handlers via internal redirect
• CVE-2024-39884: modules: source code disclosure with handlers configured via AddType. Resolving regression introduced by CVE-2024-38476 fix
• CVE-2024-40725: modules: source code disclosure with handlers configured via AddType. Resolving regression introduced by CVE-2024-39884 fix

• CVE-2024-38474: mod_rewrite: server weakness with encoded question marks in backreferences
• CVE-2024-38475: mod_rewrite: server weakness in mod_rewrite when first segment of substitution matches filesystem path
• CVE-2024-38477: mod_proxy: crash resulting in Denial of Service in mod_proxy via a malicious request
• CVE-2023-38709: http_filters: HTTP response splitting
• CVE-2024-38473: mod_proxy: server proxy encoding problem
• CVE-2024-39573: mod_rewrite: proxy handler substitution
• CVE-2024-38476: http: server use exploitable/malicious backend application output to run local handlers via internal redirect
• CVE-2024-39884: modules: source code disclosure with handlers configured via AddType. Resolving regression introduced by CVE-2024-38476 fix
• CVE-2024-40725: modules: source code disclosure with handlers configured via AddType. Resolving regression introduced by CVE-2024-39884 fix

• CVE-2024-38474: mod_rewrite: server weakness with encoded question marks in backreferences
• CVE-2024-38475: mod_rewrite: server weakness in mod_rewrite when first segment of substitution matches filesystem path
• CVE-2024-38477: mod_proxy: crash resulting in Denial of Service in mod_proxy via a malicious request
• CVE-2024-38473: mod_proxy: server proxy encoding problem
• CVE-2024-39573: mod_rewrite: proxy handler substitution
• CVE-2024-38476: http: server use exploitable/malicious backend application output to run local handlers via internal redirect
• CVE-2024-39884: modules: source code disclosure with handlers configured via AddType. Resolving regression introduced by CVE-2024-38476 fix
• CVE-2024-40725: modules: source code disclosure with handlers configured via AddType. Resolving regression introduced by CVE-2024-39884 fix

• SECURITY UPDATE: http server use exploitable/malicious backend application
  • debian/patches/CVE-2024-38476.patch: prevent server usage of exploitable/malicious backend application output to run local handlers via internal redirect
  • CVE-2024-38476
• SECURITY UPDATE: modules regression introduced by CVE-2024-38476 fix
  • debian/patches/CVE-2024-39884.patch: source code disclosure with handlers configured via AddType. Resolving regression introduced by CVE-2024-38476 fix
  • CVE-2024-39884
• SECURITY UPDATE: modules regression introduced by CVE-2024-39884 fix
  • debian/patches/CVE-2024-40725.patch: source code disclosure with handlers configured via AddType. Resolving regression introduced by CVE-2024-39884 fix
  • CVE-2024-40725
• SECURITY UPDATE: attacker allowed to execute scripts in directories permitted by the configuration but not directly reachable by any URL or source disclosure of scripts meant to only to be executed as CGI
  • debian/patches/CVE-2024-38474-38475.patch: server weakness with encoded question marks in backreferences
  • CVE-2024-38474
  • debian/patches/CVE-2024-38474-38475.patch: server weakness in mod_rewrite when first segment of substitution matches filesystem path
  • CVE-2024-38475

• SECURITY UPDATE: mod_rewrite proxy handler substitution and prefix_stat vulnerabilities
  • debian/patches/CVE-2024-38474-38475-*.patch: tighten up prefix_stat and %3f handling, add better question mark tracking to avoid UnsafeAllow3F
  • CVE-2024-38474, CVE-2024-38475

Serving WebSocket protocol upgrades over a HTTP/2 connection could result in a Null Pointer dereference, leading to a crash of the server process, degrading performance. (CVE-2024-36387) Encoding problem in mod_proxy in Apache HTTP Server 2.4.59 and earlier allows request URLs with incorrect encoding to be sent to backend services, potentially bypassing authentication via crafted requests. (CVE-2024-38473) Substitution encoding issue in mod_rewrite in Apache HTTP Server 2.4.59 and earlier allows attacker to execute scripts in directories permitted by the configuration but not directly reachable by any URL or source disclosure of scripts meant to only to be executed as CGI. Some RewriteRules that capture and substitute unsafely will now fail unless rewrite flag "UnsafeAllow3F" is specified. (CVE-2024-38474) 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. (CVE-2024-38475) Vulnerability in core of Apache HTTP Server 2.4.59 and earlier are vulnerably to information disclosure, SSRF or local script execution via backend applications whose response headers are malicious or exploitable. (CVE-2024-38476) Null pointer dereference in mod_proxy in Apache HTTP Server 2.4.59 and earlier allows an attacker to crash the server via a malicious request. (CVE-2024-38477) Potential SSRF in mod_rewrite in Apache HTTP Server 2.4.59 and earlier allows an attacker to cause unsafe RewriteRules to unexpectedly setup URL's to be handled by mod_proxy. (CVE-2024-39573) A regression in the core of Apache HTTP Server 2.4.60 ignores some use of the legacy content-type based configuration of handlers. "AddType" and similar configuration, under some circumstances where files are requested indirectly, result in source code disclosure of local content. For example, PHP scripts may be served instead of interpreted. (CVE-2024-39884)

These are all security issues fixed in the apache2-2.4.61-1.1 package on the GA media of openSUSE Tumbleweed.

This update for apache2 fixes the following issues:

Security fixes:

• CVE-2024-38477: Fixed null pointer dereference in mod_proxy (bsc#1227270)
• CVE-2024-39573: Fixed potential SSRF in mod_rewrite (bsc#1227271)
• CVE-2024-38475: Fixed improper escaping of output in mod_rewrite (bsc#1227268)

Other fixes:

• Fixed regression of security fix (bsc#1226217)

This update for apache2 fixes the following issues:

• CVE-2024-38475: Fixed improper escaping of output in mod_rewrite (bsc#1227268)
• CVE-2024-38476: Fixed server may use exploitable/malicious backend application output to run local handlers via internal redirect (bsc#1227269)

This update for apache2 fixes the following issues:

• CVE-2024-36387: Fixed DoS by null pointer in websocket over HTTP/2 (bsc#1227272)
• CVE-2024-38475: Fixed improper escaping of output in mod_rewrite (bsc#1227268)
• CVE-2024-38476: Fixed server may use exploitable/malicious backend application output to run local handlers via internal redirect (bsc#1227269)

This update for apache2 fixes the following issues:

• CVE-2024-38475: Fixed improper escaping of output in mod_rewrite (bsc#1227268)
• CVE-2024-38476: Fixed server may use exploitable/malicious backend application output to run local handlers via internal redirect (bsc#1227269)
• CVE-2024-38477: Fixed null pointer dereference in mod_proxy (bsc#1227270)
• CVE-2024-39573: Fixed potential SSRF in mod_rewrite (bsc#1227271)

This update for apache2 fixes the following issues

• CVE-2026-23918: http2: double free and possible RCE on early reset (bsc#1263957).
• CVE-2026-24072: mod_rewrite elevation of privileges via ap_expr (bsc#1263935).
• CVE-2026-28780: heap buffer overflow in mod_proxy_ajp via ajp_msg_check_header() (bsc#1264163).
• CVE-2026-29167: mod_ldap per-dir use-after-free (bsc#1267976).
• CVE-2026-29168: allocation of resources without limits in mod_md via OCSP response (bsc#1264150).
• CVE-2026-29169: NULL pointer dereference in mod_dav_lock allows server crash via malicious requests (bsc#1263956).
• CVE-2026-29170: mod_proxy_ftp XSS (bsc#1267977).
• CVE-2026-33006: mod_auth_digest timing attack allows bypass of Digest authentication (bsc#1263955).
• CVE-2026-33007: NULL pointer dereference in mod_authn_socache allows unauthenticated remote user to crash a child processes (bsc#1263954).
• CVE-2026-33523: HTTP response splitting forwarding malicious status line (bsc#1263953).
• CVE-2026-33857: off-by-one OOB reads in AJP getter functions (bsc#1263952).
• CVE-2026-34032: heap buffer overread in mod_proxy_ajp due to missing null-termination check (bsc#1263951).
• CVE-2026-34059: heap buffer overread and memory disclosure via ajp_parse_data() (bsc#1263950).
• CVE-2026-34355: mod_proxy_html buffer overflow (bsc#1267978).
• CVE-2026-34356: malicious backend servers can lead to a heap-based buffer overflow (bsc#1267955).
• CVE-2026-42535: malicious path manipulation can lead to child process crashes (bsc#1267956).
• CVE-2026-42536: processing untrusted content can lead to a heap-based buffer overflow (bsc#1267962).
• CVE-2026-43951: out-of-bound read in merge_response_headers can cause crash (bsc#1267963).
• CVE-2026-44119: improper privilege management can lead to an unauthorized read (bsc#1267965).
• CVE-2026-44185: Stack Buffer Over-Read in mod_ssl OCSP send_request (bsc#1267969).
• CVE-2026-44186: responses from an attacker-controlled FTP backend can lead to resource exhaustion and a denial of service (bsc#1267970).
• CVE-2026-44631: crafted regular expression can lead to a buffer underwrite (bsc#1267971).
• CVE-2026-48913: file handle exhaustion during request processing in mod_http2 can lead to a use-after-free (bsc#1267972).
• CVE-2026-49975: Fix cookie header accounting against LimitRequestFields (bsc#1267503).

Non security issue:

• Update to 2.4.66 (jsc#PED-16334).

Marc Stern discovered that the Apache HTTP Server incorrectly handled serving WebSocket protocol upgrades over HTTP/2 connections. A remote attacker could possibly use this issue to cause the server to crash, resulting in a denial of service. (CVE-2024-36387)

Orange Tsai discovered that the Apache HTTP Server mod_proxy module incorrectly sent certain request URLs with incorrect encodings to backends. A remote attacker could possibly use this issue to bypass authentication. (CVE-2024-38473)

Orange Tsai discovered that the Apache HTTP Server mod_rewrite module incorrectly handled certain substitutions. A remote attacker could possibly use this issue to execute scripts in directories not directly reachable by any URL, or cause a denial of service. Some environments may require using the new UnsafeAllow3F flag to handle unsafe substitutions. (CVE-2024-38474, CVE-2024-38475, CVE-2024-39573)

Orange Tsai discovered that the Apache HTTP Server incorrectly handled certain response headers. A remote attacker could possibly use this issue to obtain sensitive information, execute local scripts, or perform SSRF attacks. (CVE-2024-38476)

Orange Tsai discovered that the Apache HTTP Server mod_proxy module incorrectly handled certain requests. A remote attacker could possibly use this issue to cause the server to crash, resulting in a denial of service. (CVE-2024-38477)

It was discovered that the Apache HTTP Server incorrectly handled certain handlers configured via AddType. A remote attacker could possibly use this issue to obtain source code. (CVE-2024-39884)

USN-6885-1 fixed several vulnerabilities in Apache. This update provides the corresponding update for Ubuntu 16.04 LTS and Ubuntu 18.04 LTS.

Original advisory details:

Orange Tsai discovered that the Apache HTTP Server mod_rewrite module incorrectly handled certain substitutions. A remote attacker could possibly use this issue to execute scripts in directories not directly reachable by any URL, or cause a denial of service. Some environments may require using the new UnsafeAllow3F flag to handle unsafe substitutions. (CVE-2024-38474, CVE-2024-38475)

Orange Tsai discovered that the Apache HTTP Server incorrectly handled certain response headers. A remote attacker could possibly use this issue to obtain sensitive information, execute local scripts, or perform SSRF attacks. (CVE-2024-38476)

Orange Tsai discovered that the Apache HTTP Server mod_proxy module incorrectly handled certain requests. A remote attacker could possibly use this issue to cause the server to crash, resulting in a denial of service. (CVE-2024-38477)

USN-6885-1 fixed vulnerabilities in Apache. This update provides the corresponding updates for Ubuntu 14.04 LTS.

Original advisory details:

Orange Tsai discovered that the Apache HTTP Server mod_rewrite module incorrectly handled certain substitutions. A remote attacker could possibly use this issue to execute scripts in directories not directly reachable by any URL, or cause a denial of service. Some environments may require using the new UnsafeAllow3F flag to handle unsafe substitutions. (CVE-2024-38474, CVE-2024-38475)