Vulnerability Monitor

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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.

Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.5, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts and availability (service disruption) for affected systems. Impacting 8 products from apache, from apple, from suse and 5 others, organizations running these solutions should prioritize assessment and patching.

Historical Context

Originally identified in 2009, this vulnerability predates many modern security frameworks and practices. The vulnerability landscape of that era was characterized by different threat models and less mature defense mechanisms compared to contemporary standards.

Published

2009-06-08T01:00:00.687

Last Modified

2025-04-09T00:30:58.490

Status

Deferred

Source

[email protected]

Severity

CVSSv3.1: 7.5 (HIGH)

CVSSv2 Vector

AV:N/AC:L/Au:N/C:N/I:N/A:P

  • Access Vector: NETWORK
  • Access Complexity: LOW
  • Authentication: NONE
  • Confidentiality Impact: NONE
  • Integrity Impact: NONE
  • Availability Impact: PARTIAL
Exploitability Score

10.0

Impact Score

2.9

Weaknesses
  • Type: Primary
    CWE-776
Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Application apache apr-util < 1.3.7 Yes
Operating System apple mac_os_x < 10.6.2 Yes
Operating System suse linux_enterprise_server 9 Yes
Operating System debian debian_linux 4.0 Yes
Operating System canonical ubuntu_linux 6.06 Yes
Operating System canonical ubuntu_linux 8.04 Yes
Operating System canonical ubuntu_linux 8.10 Yes
Operating System canonical ubuntu_linux 9.04 Yes
Operating System fedoraproject fedora 9 Yes
Operating System fedoraproject fedora 10 Yes
Operating System fedoraproject fedora 11 Yes
Application oracle http_server - Yes
Application apache http_server < 2.2.12 Yes
References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For apache's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.