# CVE-2023-25690: Apache HTTP Server: HTTP request splitting with mod_rewrite and mod_proxy > Attackers can smuggle HTTP requests to bypass access controls and poison caches in specific Apache mod_proxy configurations. - **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 7 Mar 2023 - **Updated:** 18 Dec 2025 - **Also known as:** ALPINE-CVE-2023-25690, ALSA-2023:1670, ALSA-2023:1673, AZL-25605, AZL-43903, AZL-45186, BIT-apache-2023-25690, CLEANSTART-2026-XE02231, CLSA-2023-1679943745, DEBIAN-CVE-2023-25690, GHSA-wc6r-9c75-44gq, RHSA-2023:1547, RHSA-2023:1593, RHSA-2023:1596, RHSA-2023:1597, RHSA-2023:1670, RHSA-2023:1672, RHSA-2023:1673, RHSA-2023:1916, RHSA-2023:3292, RLSA-2023:1670, RLSA-2023:1673, SUSE-SU-2023:0803-1, UBUNTU-CVE-2023-25690, USN-5942-2 ## What is CVE-2023-25690? CVE-2023-25690 is a critical vulnerability in Apache Http Server, published on 7 Mar 2023. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description Some mod_proxy configurations on Apache HTTP Server versions 2.4.0 through 2.4.55 allow a HTTP Request Smuggling attack. Configurations are affected when mod_proxy is enabled along with some form of RewriteRule or ProxyPassMatch in which a non-specific pattern matches some portion of the user-supplied request-target (URL) data and is then re-inserted into the proxied request-target using variable substitution. For example, something like: RewriteEngine on RewriteRule "^/here/(.*)" "http://example.com:8080/elsewhere?$1"; [P] ProxyPassReverse /here/ http://example.com:8080/ Request splitting/smuggling could result in bypass of access controls in the proxy server, proxying unintended URLs to existing origin servers, and cache poisoning. Users are recommended to update to at least version 2.4.56 of Apache HTTP Server. Weakness: CWE-444 (Inconsistent Interpretation of HTTP Requests) ## Which versions are affected by CVE-2023-25690? 1 open source package ship an affected version, including apache. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `apache` | Bitnami | From 2.4.0 | 2.4.56 | | `httpd` | AlmaLinux:8 | All versions | 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.5 | | `httpd-devel` | AlmaLinux:8 | All versions | 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.5 | | `httpd-filesystem` | AlmaLinux:8 | All versions | 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.5 | | `httpd-manual` | AlmaLinux:8 | All versions | 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.5 | | `httpd-tools` | AlmaLinux:8 | All versions | 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.5 | | `mod_http2` | AlmaLinux:8 | All versions | 1.15.7-5.module_el8.7.0+3515+9e4fe0d6.4 | | `mod_ldap` | AlmaLinux:8 | All versions | 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.5 | | `mod_md` | AlmaLinux:8 | All versions | 1:2.0.8-8.module_el8.6.0+2872+fe0ff7aa | | `mod_md` | AlmaLinux:8 | All versions | 1:2.0.8-8.module_el8.6.0+3031+fb177b09 | | `mod_proxy_html` | AlmaLinux:8 | All versions | 1:2.4.37-51.module_el8.7.0+3515+9e4fe0d6.5 | | `mod_session` | AlmaLinux:8 | All versions | 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.5 | | `mod_ssl` | AlmaLinux:8 | All versions | 1:2.4.37-51.module_el8.7.0+3515+9e4fe0d6.5 | | `httpd` | AlmaLinux:9 | All versions | 2.4.53-7.el9_1.5 | | `httpd-core` | AlmaLinux:9 | All versions | 2.4.53-7.el9_1.5 | | `httpd-devel` | AlmaLinux:9 | All versions | 2.4.53-7.el9_1.5 | | `httpd-filesystem` | AlmaLinux:9 | All versions | 2.4.53-7.el9_1.5 | | `httpd-manual` | AlmaLinux:9 | All versions | 2.4.53-7.el9_1.5 | | `httpd-tools` | AlmaLinux:9 | All versions | 2.4.53-7.el9_1.5 | | `mod_http2` | AlmaLinux:9 | All versions | 1.15.19-3.el9_1.5 | | `mod_ldap` | AlmaLinux:9 | All versions | 2.4.53-7.el9_1.5 | | `mod_lua` | AlmaLinux:9 | All versions | 2.4.53-7.el9_1.5 | | `mod_proxy_html` | AlmaLinux:9 | All versions | 1:2.4.53-7.el9_1.5 | | `mod_session` | AlmaLinux:9 | All versions | 2.4.53-7.el9_1.5 | | `mod_ssl` | AlmaLinux:9 | All versions | 1:2.4.53-7.el9_1.5 | | `httpd` | Red Hat:enterprise_linux:7::client | All versions | 0:2.4.6-98.el7_9.7 | | `httpd-debuginfo` | Red Hat:enterprise_linux:7::client | All versions | 0:2.4.6-98.el7_9.7 | | `httpd-devel` | Red Hat:enterprise_linux:7::client | All versions | 0:2.4.6-98.el7_9.7 | | `httpd-manual` | Red Hat:enterprise_linux:7::client | All versions | 0:2.4.6-98.el7_9.7 | | `httpd-tools` | Red Hat:enterprise_linux:7::client | All versions | 0:2.4.6-98.el7_9.7 | | `mod_ldap` | Red Hat:enterprise_linux:7::client | All versions | 0:2.4.6-98.el7_9.7 | | `mod_proxy_html` | Red Hat:enterprise_linux:7::client | All versions | 1:2.4.6-98.el7_9.7 | | `mod_session` | Red Hat:enterprise_linux:7::client | All versions | 0:2.4.6-98.el7_9.7 | | `mod_ssl` | Red Hat:enterprise_linux:7::client | All versions | 1:2.4.6-98.el7_9.7 | | `httpd` | Red Hat:enterprise_linux:7::computenode | All versions | 0:2.4.6-98.el7_9.7 | | `httpd-debuginfo` | Red Hat:enterprise_linux:7::computenode | All versions | 0:2.4.6-98.el7_9.7 | | `httpd-devel` | Red Hat:enterprise_linux:7::computenode | All versions | 0:2.4.6-98.el7_9.7 | | `httpd-manual` | Red Hat:enterprise_linux:7::computenode | All versions | 0:2.4.6-98.el7_9.7 | | `httpd-tools` | Red Hat:enterprise_linux:7::computenode | All versions | 0:2.4.6-98.el7_9.7 | | `mod_ldap` | Red Hat:enterprise_linux:7::computenode | All versions | 0:2.4.6-98.el7_9.7 | Products: Apache Http Server. ## How do I fix CVE-2023-25690? Upgrade apache to 2.4.56 or later. ## Is CVE-2023-25690 being exploited? It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-25690 exists. Public exploit code: - CVE 2023 25690 Proof of concept - mod_proxy vulnerable configuration on Apache HTTP Server versions 2.4.0 - 2.4.55 leads to HTTP Request Smuggling vulnerability. (github_poc): https://github.com/dhmosfunk/CVE-2023-25690-POC - https://github.com/thanhlam-attt/CVE-2023-25690 (github_poc): https://github.com/thanhlam-attt/CVE-2023-25690 - CVE 2023 25690 Proof of concept - mod_proxy vulnerable configuration on Apache HTTP Server versions 2.4.0 - 2.4.55 leads to HTTP Request Smuggling vulnerability. (github_poc): https://github.com/oOCyginXOo/CVE-2023-25690-POC - Fix URL containing SPACES after Apache upgrade CVE-2023-25690 (github_poc): https://github.com/tbachvarova/linux-apache-fix-mod_rewrite-spaceInURL - A comprehensive collection of 12 containerized web exploitation challenges covering CVE-2023-25690, WebAuthn bypasses, HTTP/3 smuggling, and advanced XSS/RCE chains (github_poc): https://github.com/arnavps/CTF-Web-Exploitation - HTTP Request Smuggling lab: Apache 2.4.55 CRLF injection (github_poc): https://github.com/giordy0424/CVE-2023-25690_lab ## Other vulnerabilities in Apache Http Server - [CVE-2021-42013](https://insights.sbomify.com/CVE-2021-42013/): Apache HTTP Server Path Traversal (critical 9.8, exploited in the wild) - [CVE-2024-38475](https://insights.sbomify.com/CVE-2024-38475/): Apache HTTP Server Improper Escaping of Output (critical 9.1, exploited in the wild) - [CVE-2021-40438](https://insights.sbomify.com/CVE-2021-40438/): Apache HTTP Server-Side Request Forgery (SSRF) (critical 9.0, exploited in the wild) - [CVE-2019-0211](https://insights.sbomify.com/CVE-2019-0211/): Apache HTTP Server Privilege Escalation (high 7.8, exploited in the wild) - [CVE-2021-41773](https://insights.sbomify.com/CVE-2021-41773/): Apache HTTP Server Path Traversal (high 7.5, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2023-25690 and fix it if it is affected. What it is: CVE-2023-25690 is a critical vulnerability in Apache Http Server, published on 7 Mar 2023. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-25690 exists. Affected packages and fixed versions: - apache (Bitnami): affected from 2.4.0; fixed in 2.4.56 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2023-25690/ (Markdown: https://insights.sbomify.com/CVE-2023-25690/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2023-25690 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-25690 - OSV: https://osv.dev/vulnerability/CVE-2023-25690 --- From sbomify Insights: https://insights.sbomify.com/CVE-2023-25690/ Summaries are generated and may contain mistakes; the official description above is the record.