An announcement of a flaw in WordPress 2.x rated “highly critical” was posted on the Secunia blog today. The vulnerability allows a security bypass that enables malicious hackers to launch cross-site scripting attacks from remote access, which could compromise operating systems.

According to Secunia, “A vulnerability is caused due to improper access restriction of the administration section. This can be exploited to bypass the authentication mechanism and gain administrative access by setting a specially crafted cookie. This can further be exploited to execute arbitrary PHP code.”

The site also reports that “input passed to an unspecified parameter is not properly sanitised before being returned to the user. This can be exploited to execute arbitrary HTML and script code in a user’s browser session in context of an affected site.” (link)