using gitconfig to get shell access

Hello all,

If I have a bare repo that is accessed only remotely, but I allow arbitrary 'git config' keys to be set on it by the remote user (somehow), can any of them be used to make git run arbitrary commands on the server?

For example, 'hooks.showrev', is a "shell command used to format each revision in the email".

Of course that's only in contrib, but are there any like that in the main git config settings? I took a look through man git-config and offhand I couldn't find any, but if someone knows more definitively I'd appreciate hearing about it.

Thanks,

Sitaram