Friday, September 10, 2010

Firefox patches DLL load hijacking vulnerability

Mozilla has joined Apple in being among the first to fix the DLL load hijacking attack vector that continues to haunt hundreds of Windows applications. The open-source group released Firefox 3.6.9 with patches for a total of 15 vulnerabilities (11 rated critical), including the publicly known DLL load hijacking flaw that exposes Windows users to remote code execution attacks.

The majority of the 15 vulnerabilities in this Firefox patch batch could be exploited to launch drive-by download attacks from booby-trapped Web sites. According to Firefox, the DLL load hijacking issue only affects Windows XP users:

 Firefox could be used to load a malicious code library that had been planted on a victim’s computer. Firefox attempts to load dwmapi.dll upon startup as part of its platform detection, so on systems that don’t have this library, such as Windows XP, Firefox will subsequently attempt to load the library from the current working directory. An attacker could use this vulnerability to trick a user into downloading a HTML file and a malicious copy of dwmapi.dll into the same directory on their computer and opening the HTML file with Firefox, thus causing the malicious code to be executed. If the attacker was on the same network as the victim, the malicious DLL could also be loaded via a UNC path. The attack also requires that Firefox not currently be running when it is asked to open the HTML file and accompanying DLL.


Originally posted zdnet
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