Apache HTTP Server: HTTP request splitting with mod_rewrite and mod_proxy
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2023-25690
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 17:12 UTC · Revision 1
Source evidence
Apache HTTP Server: HTTP request splitting with mod_rewrite and mod_proxy
core-osv · Original sourcePublished 7 Mar 2023, 15:09 UTC
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.
osv:CVE-2023-25690
Complete source record
{
"id": "e18aa86f2b22d03b23c5d6420503b27c8f7c5dda73c90d070cbc89c01f19042c",
"url": "https://osv.dev/vulnerability/CVE-2023-25690",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Apache HTTP Server: HTTP request splitting with mod_rewrite and mod_proxy",
"summary": "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.",
"evidence": "osv:CVE-2023-25690",
"products": [],
"severity": "critical",
"structured": {
"id": "CVE-2023-25690",
"aliases": [
"BIT-apache-2023-25690",
"CVE-2023-25690"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/apache/httpd",
"type": "GIT",
"events": [
{
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{
"last_affected": "8201e867f1d4cdf61840625c6c4be901e3f1b6ba"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "2.4.0"
},
{
"last_affected": "2.4.55"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-25690.json"
}
}
],
"modified": "2026-10-28T02:30:30.585236407Z",
"provider": "osv",
"references": [
"https://lists.debian.org/debian-lts-announce/2023/04/msg00028.html",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/25xxx/CVE-2023-25690.json",
"https://httpd.apache.org/security/vulnerabilities_24.html",
"https://nvd.nist.gov/vuln/detail/CVE-2023-25690",
"https://security.gentoo.org/glsa/202309-01"
],
"provider_metadata": {
"cwe_ids": [
"CWE-444"
],
"cna_assigner": "apache",
"unresolved_ranges": [
{
"extracted_events": [
{
"range": [
{
"introduced": "2.4.0"
},
{
"last_affected": "2.4.55"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
}
]
}
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/25xxx/CVE-2023-25690.json"
}
},
"related_cves": [
{
"value": "CVE-2023-25690",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 497737,
"published_at": "2023-03-07T15:09:03.08+00:00"
}