Is CVE-2009-3720 actively exploited?

CVE-2009-3720 has no public evidence of in-the-wild exploitation as of 2025-04-09.

What is the CVSS score for CVE-2009-3720?

CVE-2009-3720 has a CVSS score of 5 (UNKNOWN severity). Vector: AV:N/AC:L/Au:N/C:N/I:N/A:P.

How do I patch CVE-2009-3720?

Patch guidance is available from libexpat project security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2009-3720.

CVE-2009-3720 - remediation guidance & executive summary

Q: Which products are affected by CVE-2009-3720?

3 products: libexpat project libexpat, apache http server, apache http server.

Description

The updatePosition function in lib/xmltok_impl.c in libexpat in Expat 2.0.1, as used in Python, PyXML, w3c-libwww, and other software, allows context-dependent attackers to cause a denial of service (application crash) via an XML document with crafted UTF-8 sequences that trigger a buffer over-read, a different vulnerability than CVE-2009-2625.

CVSS Metrics

Vector: AV:N/AC:L/Au:N/C:N/I:N/A:P
Access Vector: network
Access Cmplx: low
Auth: none
Confidentiality: none
Integrity: none
Availability: partial
Weaknesses: NVD-CWE-noinfo

Metadata

Primary Vendor: LIBEXPAT_PROJECT
Published: 11/3/2009
Last Modified: 4/9/2025
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

libexpat_project : libexpatapache : http_serverapache : http_server

Remediation Guidance

Executive Summary

Cite this page

CVE-2009-3720. CVEDatabase.com. Retrieved 1 May 2026. https://cvedatabase.com/cve/CVE-2009-3720

View on NIST NVD

CVE-2009-3720 vulnerability