VDB-50685 · CVE-2009-3720 · BID 36097

James Clark expat 2.0.1 lib/xmltok_impl.c updatePosition denial of service

CVSS Meta Temp Score
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CTI Interest Score
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A vulnerability was found in James Clark expat 2.0.1. It has been classified as problematic. This affects the function updatePosition in the library lib/xmltok_impl.c. The manipulation with an unknown input leads to a denial of service vulnerability. CWE is classifying the issue as CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. This is going to have an impact on availability. The summary by CVE is:

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.

The weakness was published 11/03/2009 (Website). The advisory is shared at redhat.com. This vulnerability is uniquely identified as CVE-2009-3720. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details and a public exploit are known.

The exploit is shared for download at securityfocus.com. It is declared as proof-of-concept. The vulnerability scanner Nessus provides a plugin with the ID 67979 (Oracle Linux 4 / 5 : PyXML (ELSA-2010-0002)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Oracle Linux Local Security Checks. The commercial vulnerability scanner Qualys is able to test this issue with plugin 216004 (VMWare ESXi 4.1.0 Patch Release ESXi410-201201001 Missing (KB2009137)).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at Tenable (67979). Similar entries are available at 5322, 51038, 53383 and 53381.





CPE 2.3info

CPE 2.2info


VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.0

VulDB Base Score: 5.3
VulDB Temp Score: 5.0
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Class: Denial of service
CWE: CWE-404
ATT&CK: T1499

Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Download: 🔍

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Nessus ID: 67979
Nessus Name: Oracle Linux 4 / 5 : PyXML (ELSA-2010-0002)
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OpenVAS ID: 68923
OpenVAS Name: Slackware Advisory SSA:2011-041-02 expat
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Threat Intelligenceinfo

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Recommended: no mitigation known
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01/17/2009 🔍
10/16/2009 +271 days 🔍
11/03/2009 +18 days 🔍
11/03/2009 +0 days 🔍
11/03/2009 +0 days 🔍
11/08/2009 +5 days 🔍
07/12/2013 +1342 days 🔍
03/18/2015 +614 days 🔍
08/25/2021 +2352 days 🔍


Advisory: redhat.com
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2009-3720 (🔍)

Vulnerability Center: 23934 - Expat 2.0.1 updatePosition Function Vulnerability Allows Remote DoS via Crafted UTF-8 Sequences, Medium
SecurityFocus: 36097 - Expat UTF-8 Character XML Parsing Remote Denial of Service Vulnerability

scip Labs: https://www.scip.ch/en/?labs.20161013
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Created: 03/18/2015 03:15 PM
Updated: 08/25/2021 05:13 AM
Changes: 03/18/2015 03:15 PM (66), 02/16/2017 10:10 AM (11), 08/25/2021 05:05 AM (4), 08/25/2021 05:13 AM (1)
Complete: 🔍


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