bash: Remote code execution

GNU Bash through 4.3 bash43-025 processes trailing strings after
certain malformed function definitions in the values of environment
variables, which allows remote attackers to write to files or possibly
have unknown other impact via a crafted environment, as demonstrated by
vectors involving the ForceCommand feature in OpenSSH sshd, the mod_cgi
and mod_cgid modules in the Apache HTTP Server, scripts executed by
unspecified DHCP clients, and other situations in which setting the
environment occurs across a privilege boundary from Bash execution.