CVE-2009-3720
expat: buffer over-read and crash on XML with malformed UTF-8 sequences
Severity
ModerateRed Hat Product Security
CVSS 2.0
Review impact separately from score.
Published · January 17, 2009
Updated · November 21, 2025
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 score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 2.0 · 5AV:N/AC:L/Au:N/C:N/I:N/A:P
CWE not specified