cgi/b on the BT Home Hub router allows remote attackers to bypass authentication, and read or modify administrative settings or make arbitrary VoIP telephone calls, by placing a character at the end of the PATH_INFO, as demonstrated by (1) %5C (encoded backslash), (2) '%' (percent), and (3) '~' (tilde). NOTE: the '/' (slash) vector is already covered by CVE-2007-5383.

The Thomson/Alcatel SpeedTouch 7G router, as used for the BT Home Hub 6.2.6.B and earlier, allows remote attackers on an intranet to bypass authentication and gain administrative access via vectors including a '/' (slash) character at the end of the PATH_INFO to cgi/b, aka "double-slash auth bypass." NOTE: remote attackers outside the intranet can exploit this by leveraging a separate CSRF vulnerability. NOTE: SpeedTouch 780 might also be affected by some of these issues.