Telerik Fiddler through 5.0.20202.18177 allows attackers to execute arbitrary programs via a hostname with a trailing space character, followed by --utility-and-browser --utility-cmd-prefix= and the pathname of a locally installed program. The victim must interactively choose the Open On Browser option. Fixed in version 5.0.20204.

Telerik Fiddler v5.0.20182.28034 doesn't verify the hash of EnableLoopback.exe before running it, which could lead to code execution or local privilege escalation by replacing the original EnableLoopback.exe.