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Fencer Vulns
medium 5.0

CVE-2009-3560 json

The big2_toUtf8 function in lib/xmltok.c in libexpat in Expat 2.0.1, as used in the XML-Twig module for Perl, allows context-dependent atta…

published 2009-12-04 16 y ago modified 2026-06-16 4 mo ago also EUVD-2009-3541

cvss
5.0
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
24.3%
EPSS 24.3% chance of exploitation in 30 days, percentile 97%
public exploits
0
none known

Summary

The big2_toUtf8 function in lib/xmltok.c in libexpat in Expat 2.0.1, as used in the XML-Twig module for Perl, allows context-dependent attackers to cause a denial of service (application crash) via an XML document with malformed UTF-8 sequences that trigger a buffer over-read, related to the doProlog function in lib/xmlparse.c, a different vulnerability than CVE-2009-2625 and CVE-2009-3720.

Patch / fix

  • apache http_server 2.0.64, 2.2.17
  • tla Debian 12 1.3.5+dfsg-15
  • gdcm Debian 14, Debian 13, Debian 12 2.0.14-2
  • poco Debian 14, Debian 13, Debian 12 1.3.6p1-1
  • tdom Debian 14, Debian 13, Debian 12 0.8.3~20080525-1
  • cmake Debian 14, Debian 13, Debian 12 2.6.0-6
  • coin3 Debian 14, Debian 13, Debian 12 4.0.0~CMake~6f54f1602475+ds1-1
  • expat Debian 14, Debian 13, Debian 12 2.0.1-6
  • mcabber Debian 13, Debian 12 0.10.0-1

debian advisories DEBIAN-CVE-2009-3560

  • expat RHEL 3 1.95.5-6.2
  • expat RHEL 4 1.95.7-4.el4_8.2
  • expat RHEL 5 1.95.8-8.3.el5_4.2

red hat advisories RHSA-2009:1625

  • expat openSUSE Tumbleweed 2.2.0-3.1
  • apache2 openSUSE Tumbleweed 2.4.23-4.1
  • apr-util openSUSE Tumbleweed 1.5.4-4.4
  • apr-util openSUSE Tumbleweed 1.6.1-8.1

opensuse advisories openSUSE-SU-2024:10077-1openSUSE-SU-2024:10268-1openSUSE-SU-2024:10568-1openSUSE-SU-2024:11586-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2009-3560 updated cvss 5.0

expat: buffer over-read and crash in big2_toUtf8() on XML with malformed UTF-8 sequences

  • Red Hat Enterprise Linux 5 xmlrpc-c
    affected: no fix planned “Will not fix”
  • Red Hat Desktop version 3 expat 1.95.5-6.2 Red Hat Enterprise Linux (v. 5 server) expat 1.95.8-8.3.el5_4.2 Red Hat Enterprise Linux AS version 3 expat 1.95.5-6.2 Red Hat Enterprise Linux AS version 4 expat 1.95.7-4.el4_8.2 Red Hat Enterprise Linux Desktop (v. 5 client) expat 1.95.8-8.3.el5_4.2 Red Hat Enterprise Linux Desktop version 4 expat 1.95.7-4.el4_8.2
    +5 more products
    Red Hat Enterprise Linux Desktop Workstation (v. 5 client) expat 1.95.8-8.3.el5_4.2 Red Hat Enterprise Linux ES version 3 expat 1.95.5-6.2 Red Hat Enterprise Linux ES version 4 expat 1.95.7-4.el4_8.2 Red Hat Enterprise Linux WS version 3 expat 1.95.5-6.2 Red Hat Enterprise Linux WS version 4 expat 1.95.7-4.el4_8.2
    fixed: vendor fix RHSA-2009:1625
  • Red Hat JBoss Enterprise Application Platform 6.4
    fixed: vendor fix RHSA-2017:3239
  • Red Hat JBoss Web Server 1.0
    fixed: vendor fix RHSA-2011:0896
  • Red Hat Enterprise Linux 6 expat, compat-expat1 Red Hat Enterprise Linux 7 expat
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

24.31% chance of exploitation in the next 30 days, higher than 97% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • mail.python.org http://mail.python.org/pipermail/expat-bugs/2009-November/002846.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Classification

Weakness
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.