Common Vulnerabilities and Exposures assigned an identifier CVE-2003-1564 to the following vulnerability:
libxml2, possibly before 2.5.0, does not properly detect recursion
during entity expansion, which allows context-dependent attackers to
cause a denial of service (memory and CPU consumption) via a crafted
XML document containing a large number of nested entity references,
aka the "billion laughs attack."
Created attachment 315726 [details]
Public test case
libxml2 versions as shipped in Red Hat Enterprise Linux 3, 4 and 5 are based on upstream version that detects this this type of attack. Additionally, detection was further improved recently in the patch for the "attribute value" variant of this attack known as CVE-2008-3281 (see bug #458086 and bug #460396).
This issue was addressed in:
Red Hat Enterprise Linux: