chicken -- multiple vulnerabilities

Peter Bex reports:

A buffer overflow error was found in the POSIX unit’s procedures
process-execute and process-spawn.
Additionally, a memory leak existed in this code, which would be
triggered when an error is raised during argument and environment
processing.

Irregex versions before 0.9.6 contain a resource exhaustion
vulnerability: when compiling deeply nested regexes containing the
“+” operator due to exponential expansion behaviour.