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Public proof of conceptFix available

CVE-2009-1955

A public proof of concept exists; no exploitation attested.

  • Published2009-06-08
  • WeaknessCWE-776

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2009-06-01Exploit-DB entryExploit-DB
  2. 2009-06-0801:00CVE publishedNVD
  3. 2026-10-2319:23EPSS crossed 10 %FIRST EPSS

Observed activity

isMalicious corpus · updated 2026-11-04 03:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2009-1955?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2009-1955?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Canonical ubuntu linux
BranchAffectedFixed in
6.6= 6.06no fix published
8.4= 8.04no fix published
8.10= 8.10no fix published
9.4= 9.04no fix published
Fedoraproject fedora
BranchAffectedFixed in
9.x= 9no fix published
10.x= 10no fix published
11.x= 11no fix published
Apache apr-util
BranchAffectedFixed in
1.3< 1.3.71.3.7

5 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • antRed Hat:certificate_system:7.3all versions · fixed in 0:1.6.5-1jpp_1rh
  • apache2openSUSE:Tumbleweedall versions · fixed in 2.4.23-4.1
  • apr-utilRed Hat:enterprise_linux:5::serverall versions · fixed in 0:1.2.7-7.el5_3.1and 3 other packages
  • apr-utilRed Hat:enterprise_linux:5::client_workstationall versions · fixed in 0:1.2.7-7.el5_3.1and 2 other packages
  • apr-utilRed Hat:enterprise_linux:5::clientall versions · fixed in 0:1.2.7-7.el5_3.1and 2 other packages
  • apr-utilRed Hat:enterprise_linux:4::wsall versions · fixed in 0:0.9.4-22.el4_8.1and 2 other packages
  • apr-utilRed Hat:enterprise_linux:4::esall versions · fixed in 0:0.9.4-22.el4_8.1and 2 other packages
  • apr-utilRed Hat:enterprise_linux:4::desktopall versions · fixed in 0:0.9.4-22.el4_8.1and 2 other packages

34 more package ranges on OSV.dev

Vendor advisories

  • RHSA-2010:0602 Red Hat Product Security114 products fixed

    Red Hat Security Advisory: Red Hat Certificate System 7.3 security update

Full record on NVD

Fix

  1. Vendor fix Red Hat Product Security RHSA-2010:0602 · 114 productsBefore applying this update, make sure all previously-released errata relevant to your system have been applied. This update is available via the Red Hat Network. Details on how to use the Red Hat Network to apply this update are available at http://kbase.redhat.com/faq/docs/DOC-11259

Advisories and patches

Detection

read 2026-11-03 22:42 UTC
Nuclei template
none so far
ProjectDiscovery
Exploit-DB
EDB-8842
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2009-06-08
Last Modified
2026-06-16
NVD status
Modified
GitHub Advisory
GHSA-hfr6-pxvf-frf7

Frequently asked questions

What is 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 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.

Is CVE-2009-1955 actively exploited?

Active exploitation of CVE-2009-1955 has not been confirmed. Its EPSS score was 53.0% on 2026-11-03, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2009-1955?

CVE-2009-1955 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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Sources for this record