On Nov 27, 2020, at 9:44 AM, Lars Kiesow <lkiesow@uos.de> wrote:
Hi everyone, I'm trying to mask the caller_id_name in a FreeSWITCH dialplan to prevent the real phone numbers to show up in our conferencing software. Someone sent me the following lines:
<action application="set" data="MASK=${system echo ${caller_id_name} | grep -o -P '.{0,4}$' | sed 's/^/xxx-xxx-/' }"/> <action application="set_profile_var" data="caller_id_name=${MASK}"/>
While this works perfectly and does exactly what I want, I'm unsure about potential security risks.
Its a good thing to be concerned with, yes thats real
The caller_id_name ends up in a shell command after all and I'm wondering if someone could send a name like `; rm /*` (you get the idea).
Is this safe? Is the caller_id_name sanitized? Is there a better way to do something like this?
No not safe. Check out https://freeswitch.org/confluence/display/FREESWITCH/mod_dptools%3A+regex <https://freeswitch.org/confluence/display/FREESWITCH/mod_dptools:+regex>
Best regards, Lars