Microsoft Internet Explorer 5 / Firefox 0.8 / OmniWeb 4.x - URI Protocol Handler Arbitrary File Creation/Modification

source: https://www.securityfocus.com/bid/10336/info

A vulnerability has been identified in multiple products from multiple vendors that may allow a remote attacker to create or modify arbitrary files; these issues relate to the processing of URI requests via various protocol handlers including telnet, rlogin, ssh and mailto.

The vulnerability presents itself because applications fail to validate URI input; if a '-' character precedes the host name it is possible to pass options to an application that handles the protocol. 

Successful exploitation of this issue may allow a remote attacker to create or modify arbitrary files, resulting in a denial of service condition in the browser. The attack would occur in the context of the user running the vulnerable browser.

telnet://-fFileName
telnet://-nFilename