kenmirrors/asterisk
1
0
Fork 0
mirror of https://github.com/asterisk/asterisk.git synced 2025-09-02 19:16:15 +00:00
Code Issues Packages Projects Releases Wiki Activity

security: Inhibit execution of privilege escalating functions

Browse Source 
This patch allows individual dialplan functions to be marked as
'dangerous', to inhibit their execution from external sources.

A 'dangerous' function is one which results in a privilege escalation.
For example, if one were to read the channel variable SHELL(rm -rf /)
Bad Things(TM) could happen; even if the external source has only read
permissions.

Execution from external sources may be enabled by setting
'live_dangerously' to 'yes' in the [options] section of asterisk.conf.
Although doing so is not recommended.

Also, the ABI was changed to something more reasonable, since Asterisk
12 does not yet have a public release.

(closes issue ASTERISK-22905)
Review: http://reviewboard.digium.internal/r/432/
........

Merged revisions 403913 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........

Merged revisions 403917 from http://svn.asterisk.org/svn/asterisk/branches/11
........

Merged revisions 403959 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@403960 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
David M. Lee
2013-12-16 19:11:51 +00:00
parent 00dcee2a64
commit 744556c01d
12 changed files with 418 additions and 37 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
funcs/func_shell.c
View File

@@ -88,11 +88,17 @@ static int shell_helper(struct ast_channel *chan, const char *cmd, char *data,
</syntax>
<description>
<para>Collects the output generated by a command executed by the system shell</para>
<para>Example: <literal>Set(foo=${SHELL(echo \bar\)})</literal></para>
<note><para>The command supplied to this function will be executed by the
system's shell, typically specified in the SHELL environment variable. There
are many different system shells available with somewhat different behaviors,
so the output generated by this function may vary between platforms.</para></note>
<para>Example: <literal>Set(foo=${SHELL(echo bar)})</literal></para>
<note>
<para>The command supplied to this function will be executed by the
system's shell, typically specified in the SHELL environment variable. There
are many different system shells available with somewhat different behaviors,
so the output generated by this function may vary between platforms.</para>
<para>If <literal>live_dangerously</literal> in <literal>asterisk.conf</literal>
is set to <literal>no</literal>, this function can only be executed from the
dialplan, and not directly from external protocols.</para>
</note>
</description>
</function>
@@ -109,7 +115,7 @@ static int unload_module(void)
static int load_module(void)
{
return ast_custom_function_register(&shell_function);
return ast_custom_function_register_escalating(&shell_function, AST_CFE_READ);
}
AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Collects the output generated by a command executed by the system shell");