Re: Terminal escape sequences - the new XSS for admins?

[Michal Zalewski <lcamtuf () coredump cx>]

> This is why I am not happy about this thread's apparent decision to
> dismiss unsafe handling of likely terminal escapes (the known ranges) in
> untrusted input in individual programs as long as there are no known
> worse-than-DoS intentional features in modern terminal emulators.
> I would be happier to have this layer of security as well.  Besides, DoS
> issues are a concern too, and are obviously available as intentional
> features in typical terminal emulators.

I definitely think it deserves a closer look. Here are three recent
finds that kcwu reported after apparently testing GNU screen with
afl-fuzz:

https://savannah.gnu.org/bugs/?45713
https://savannah.gnu.org/bugs/?45715
https://savannah.gnu.org/bugs/?45714

While I suspect that command injection bugs (the thing that started
the thread) are fairly rare, I fully expect that escape sequence
handling is under-audited and that there's plenty of mem corruption
bugs to be found.

(Cc:ing Hanno in case he wants to have a look.)

/mz