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NVD / CVE Program· CNA apache

CVE-2023-25690: Apache HTTP Server: HTTP request splitting with mod_rewrite and mod_proxy

Noroxi assessment

Priority: This week (action score 64/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 84.5% (FIRST EPSS); higher than 99.7% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: httpd (AlmaLinux:8) 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.5; httpd-devel (AlmaLinux:8) 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.5; httpd-filesystem (AlmaLinux:8) 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.5.
  • Mentioned 6 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Don’t wait for the next maintenance window. Upgrade to httpd (AlmaLinux:8) 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.5; httpd-devel (AlmaLinux:8) 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.5; httpd-filesystem (AlmaLinux:8) 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.5 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

CriticalCVSS 9.8 · v3.1—Proof of concept Fix available
Published
Mar 7, 2023
Updated
Jun 17, 2026
EPSS
84.5% · 99th percentile

Report tools

JSON

Action score

64

This week

Don’t wait for the next maintenance window.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
25 / 30 · 84.5%

CISA SSVC decision

Exploitation
proof of concept
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

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  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

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VendorProduct
apachehttp server

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Is Apache HTTP Server on your server exposed to the internet?

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Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • apache http server2.4.0 and later · up to 2.4.55 inclusive

Versions reported by the vendor

Affected version ranges reported by the assigning authority (apache). Independent of NVD's CPE analysis and usually ahead of it.

  • Apache Software Foundation Apache HTTP Server

    • 2.4.0 and later · up to and including 2.4.55affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:8httpdbefore 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.52.4.37-51.module_el8.7.0+3515+9e4fe0d6.5
AlmaLinux:8httpd-develbefore 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.52.4.37-51.module_el8.7.0+3515+9e4fe0d6.5
AlmaLinux:8httpd-filesystembefore 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.52.4.37-51.module_el8.7.0+3515+9e4fe0d6.5
AlmaLinux:8httpd-manualbefore 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.52.4.37-51.module_el8.7.0+3515+9e4fe0d6.5
AlmaLinux:8httpd-toolsbefore 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.52.4.37-51.module_el8.7.0+3515+9e4fe0d6.5
AlmaLinux:8mod_http2before 1.15.7-5.module_el8.7.0+3515+9e4fe0d6.41.15.7-5.module_el8.7.0+3515+9e4fe0d6.4
AlmaLinux:8mod_ldapbefore 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.52.4.37-51.module_el8.7.0+3515+9e4fe0d6.5
AlmaLinux:8mod_mdbefore 1:2.0.8-8.module_el8.6.0+2872+fe0ff7aa1:2.0.8-8.module_el8.6.0+2872+fe0ff7aa
AlmaLinux:8mod_mdbefore 1:2.0.8-8.module_el8.6.0+3031+fb177b091:2.0.8-8.module_el8.6.0+3031+fb177b09
AlmaLinux:8mod_proxy_htmlbefore 1:2.4.37-51.module_el8.7.0+3515+9e4fe0d6.51:2.4.37-51.module_el8.7.0+3515+9e4fe0d6.5
AlmaLinux:8mod_sessionbefore 2.4.37-51.module_el8.7.0+3515+9e4fe0d6.52.4.37-51.module_el8.7.0+3515+9e4fe0d6.5
AlmaLinux:8mod_sslbefore 1:2.4.37-51.module_el8.7.0+3515+9e4fe0d6.51:2.4.37-51.module_el8.7.0+3515+9e4fe0d6.5
AlmaLinux:9httpdbefore 2.4.53-7.el9_1.52.4.53-7.el9_1.5
AlmaLinux:9httpd-corebefore 2.4.53-7.el9_1.52.4.53-7.el9_1.5
AlmaLinux:9httpd-develbefore 2.4.53-7.el9_1.52.4.53-7.el9_1.5
AlmaLinux:9httpd-filesystembefore 2.4.53-7.el9_1.52.4.53-7.el9_1.5
AlmaLinux:9httpd-manualbefore 2.4.53-7.el9_1.52.4.53-7.el9_1.5
AlmaLinux:9httpd-toolsbefore 2.4.53-7.el9_1.52.4.53-7.el9_1.5
AlmaLinux:9mod_http2before 1.15.19-3.el9_1.51.15.19-3.el9_1.5
AlmaLinux:9mod_ldapbefore 2.4.53-7.el9_1.52.4.53-7.el9_1.5
AlmaLinux:9mod_luabefore 2.4.53-7.el9_1.52.4.53-7.el9_1.5
AlmaLinux:9mod_proxy_htmlbefore 1:2.4.53-7.el9_1.51:2.4.53-7.el9_1.5
AlmaLinux:9mod_sessionbefore 2.4.53-7.el9_1.52.4.53-7.el9_1.5
AlmaLinux:9mod_sslbefore 1:2.4.53-7.el9_1.51:2.4.53-7.el9_1.5

+96

Same product

apache: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-42013Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773)KEV
    99Now
  • CVE-2021-41773Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49KEV
    99Now
  • CVE-2024-38475Apache HTTP Server weakness in mod_rewrite when first segment of substitution matches filesystem path.KEV
    96Now

Published before and after this one in the same product

  • ← EarlierCVE-2022-36760Jan 17, 2023 · Apache HTTP Server: mod_proxy_ajp Possible request smuggling
    37Monitor
  • ← EarlierCVE-2022-37436Jan 17, 2023 · Apache HTTP Server: mod_proxy prior to 2.4.55 allows a backend to trigger HTTP response splitting
    38Monitor
  • Later →CVE-2023-27522Mar 7, 2023 · Apache HTTP Server: mod_proxy_uwsgi HTTP response splitting
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
almalinux:httpd2.4.53-7.el9_1.5 · AlmaLinux:9Package registry (OSV)
almalinux:httpd-core2.4.53-7.el9_1.5 · AlmaLinux:9Package registry (OSV)
almalinux:httpd-devel2.4.53-7.el9_1.5 · AlmaLinux:9Package registry (OSV)
almalinux:httpd-filesystem2.4.53-7.el9_1.5 · AlmaLinux:9Package registry (OSV)
almalinux:httpd-manual2.4.53-7.el9_1.5 · AlmaLinux:9Package registry (OSV)
almalinux:httpd-tools2.4.53-7.el9_1.5 · AlmaLinux:9Package registry (OSV)
almalinux:mod_http21.15.19-3.el9_1.5 · AlmaLinux:9Package registry (OSV)
almalinux:mod_ldap2.4.53-7.el9_1.5 · AlmaLinux:9Package registry (OSV)
almalinux:mod_lua2.4.53-7.el9_1.5 · AlmaLinux:9Package registry (OSV)
almalinux:mod_proxy_html1:2.4.53-7.el9_1.5 · AlmaLinux:9Package registry (OSV)
almalinux:mod_session2.4.53-7.el9_1.5 · AlmaLinux:9Package registry (OSV)
almalinux:mod_ssl1:2.4.53-7.el9_1.5 · AlmaLinux:9Package registry (OSV)
alpine:apache22.4.56-r0 · Alpine:v3.14Package registry (OSV)
debian:apache22.4.56-1 · Debian:12Package registry (OSV)
opensuse:apache22.4.51-150400.6.11.1 · openSUSE:Leap 15.4Package registry (OSV)
red hat:httpd0:2.4.37-16.module+el8.1.0+18511+ffefe478.6 · Red Hat:rhel_e4s:8.1::appstreamPackage registry (OSV)
red hat:httpd-debuginfo0:2.4.37-16.module+el8.1.0+18511+ffefe478.6 · Red Hat:rhel_e4s:8.1::appstreamPackage registry (OSV)
red hat:httpd-debugsource0:2.4.37-16.module+el8.1.0+18511+ffefe478.6 · Red Hat:rhel_e4s:8.1::appstreamPackage registry (OSV)
red hat:httpd-devel0:2.4.37-16.module+el8.1.0+18511+ffefe478.6 · Red Hat:rhel_e4s:8.1::appstreamPackage registry (OSV)
red hat:httpd-filesystem0:2.4.37-16.module+el8.1.0+18511+ffefe478.6 · Red Hat:rhel_e4s:8.1::appstreamPackage registry (OSV)
red hat:httpd-manual0:2.4.37-16.module+el8.1.0+18511+ffefe478.6 · Red Hat:rhel_e4s:8.1::appstreamPackage registry (OSV)
red hat:httpd-tools0:2.4.37-16.module+el8.1.0+18511+ffefe478.6 · Red Hat:rhel_e4s:8.1::appstreamPackage registry (OSV)
red hat:httpd-tools-debuginfo0:2.4.37-16.module+el8.1.0+18511+ffefe478.6 · Red Hat:rhel_e4s:8.1::appstreamPackage registry (OSV)
red hat:mod_http20:1.11.3-3.module+el8.1.0+18514+ae5f89d3.3 · Red Hat:rhel_e4s:8.1::appstreamPackage registry (OSV)
red hat:mod_http2-debuginfo0:1.11.3-3.module+el8.1.0+18514+ae5f89d3.3 · Red Hat:rhel_e4s:8.1::appstreamPackage registry (OSV)
red hat:mod_http2-debugsource0:1.11.3-3.module+el8.1.0+18514+ae5f89d3.3 · Red Hat:rhel_e4s:8.1::appstreamPackage registry (OSV)
red hat:mod_ldap0:2.4.37-16.module+el8.1.0+18511+ffefe478.6 · Red Hat:rhel_e4s:8.1::appstreamPackage registry (OSV)
rocky linux:httpd0:2.4.53-7.el9_1.5 · Rocky Linux:9Package registry (OSV)
rocky linux:mod_http20:1.15.19-3.el9_1.5 · Rocky Linux:9Package registry (OSV)
rocky linux:mod_md1:2.0.8-8.module+el8.5.0+695+1fa8055e · Rocky Linux:8Package registry (OSV)

+2

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×7

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:12023-04-25
Proof-of-concept repository on GitHubstars:2882023-05-22
Proof-of-concept repository on GitHubstars:42023-12-04
Proof-of-concept repository on GitHubstars:22025-06-01
Proof-of-concept repository on GitHubstars:12026-04-05
Proof-of-concept repository on GitHubstars:02026-07-16
Proof-of-concept repository on GitHubstars:02026-09-25

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. First PoC+48 d
  3. TodayNov 4, 2026+1338 d

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-444 · Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records