diff options
| author | Corey Farrell <git@cfware.com> | 2017-07-01 20:24:27 -0400 |
|---|---|---|
| committer | Joshua Colp <jcolp@digium.com> | 2017-08-30 18:43:38 +0000 |
| commit | 1bf3dfffd7f98f7259c04e3276c2f9ef1704eba7 (patch) | |
| tree | 78fc30e98006152c491c3408e01c8889120ef45e /funcs | |
| parent | 36c1513148d85af188e7e740fb1d6524c17fc3bf (diff) | |
AST-2017-006: Fix app_minivm application MinivmNotify command injection
An admin can configure app_minivm with an externnotify program to be run
when a voicemail is received. The app_minivm application MinivmNotify
uses ast_safe_system() for this purpose which is vulnerable to command
injection since the Caller-ID name and number values given to externnotify
can come from an external untrusted source.
* Add ast_safe_execvp() function. This gives modules the ability to run
external commands with greater safety compared to ast_safe_system().
Specifically when some parameters are filled by untrusted sources the new
function does not allow malicious input to break argument encoding. This
may be of particular concern where CALLERID(name) or CALLERID(num) may be
used as a parameter to a script run by ast_safe_system() which could
potentially allow arbitrary command execution.
* Changed app_minivm.c:run_externnotify() to use the new ast_safe_execvp()
instead of ast_safe_system() to avoid command injection.
* Document code injection potential from untrusted data sources for other
shell commands that are under user control.
ASTERISK-27103
Change-Id: I7552472247a84cde24e1358aaf64af160107aef1
Diffstat (limited to 'funcs')
| -rw-r--r-- | funcs/func_shell.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/funcs/func_shell.c b/funcs/func_shell.c index 0398cd839..fe1debe88 100644 --- a/funcs/func_shell.c +++ b/funcs/func_shell.c @@ -82,6 +82,11 @@ static int shell_helper(struct ast_channel *chan, const char *cmd, char *data, <syntax> <parameter name="command" required="true"> <para>The command that the shell should execute.</para> + <warning><para>Do not use untrusted strings such as <variable>CALLERID(num)</variable> + or <variable>CALLERID(name)</variable> as part of the command parameters. You + risk a command injection attack executing arbitrary commands if the untrusted + strings aren't filtered to remove dangerous characters. See function + <variable>FILTER()</variable>.</para></warning> </parameter> </syntax> <description> |