* Mozilla version 1.6 for Windows
* Mozilla Firefox version 1.0 for Linux
Mozilla's mail client and Mozilla's web browser support the XBM graphic files standard. A security flaw in the way softwares handles these images, allow a malicious user to perform a denial-of-service attack.
The X BitMap data is stored as ASCII data, in the file's beginning of the file there are two '#define' statements. The following is an example of a 16x16 XBM bitmap, named Esempio.xbm: #define Esempio_width 16
#define Esempio_height 16
Opening file, Mozilla read width and height values from '#define' statement and try to allocate enough memory to display image. Defining high values to width and height parameters would cause the application to crash. This vulnerability can be exploited by sending an e-mail containing a specially crafted image, or by tricking a user into a malicious website.