Description
Cytrix has detected that the Version of Apache HTTP Server being used is vulnerable to ‘expat Denial of Service’ (DoS).
CVE-2009-3720 occurs when a ‘buffer over-read’ flaw is found in the bundled ‘expat’ library.
This vulnerability is different than CVE-2009-2625, which caused by the ‘XMLScanner.java’.
The ‘updatePosition’ function being used in ‘lib/xmltok_impl.c’ in libexpat is your Expat version may allow context-dependent attackers to cause a Denial of Service (DoS) by crashing the application.
That can be done by parsing an XML document with crafted UTF-8 sequences that will trigger a buffer over-read.
It could lead to a decrease in performance and interruptions in the availability of resources.
Recommendation
It’s worth mentioning that the asset is vulnerable only if Apache is enabled to parse an untrusted XML document.
Check the configuration of your web server to validate the case.
To fix CVE-2009-3720, upgrade the version of Apache HTTP Server being used to either 2.0.64 or 2.2.17.
References
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-3720