Asterisk: Multiple vulnerabilities
Gentoo Linux Security Advisory
||GLSA 200610-15 / asterisk
||October 30, 2006
||January 30, 2007: 02
All supported architectures
Asterisk is vulnerable to the remote execution of arbitrary code or a
Denial of Service.
Asterisk is an open source implementation of a telephone private branch
Asterisk contains buffer overflows in channels/chan_mgcp.c from the
MGCP driver and in channels/chan_skinny.c from the Skinny channel
driver for Cisco SCCP phones. It also dangerously handles
client-controlled variables to determine filenames in the Record()
function. Finally, the SIP channel driver in channels/chan_sip.c could
use more resources than necessary under unspecified circumstances.
A remote attacker could execute arbitrary code by sending a crafted
audit endpoint (AUEP) response, by sending an overly large Skinny
packet even before authentication, or by making use of format strings
specifiers through the client-controlled variables. An attacker could
also cause a Denial of Service by resource consumption through the SIP
There is no known workaround for the format strings vulnerability at
this time. You can comment the lines in /etc/asterisk/mgcp.conf,
/etc/asterisk/skinny.conf and /etc/asterisk/sip.conf to deactivate the
three vulnerable channel drivers. Please note that the MGCP channel
driver is disabled by default.
All Asterisk users should upgrade to the latest version:
Code Listing 3.1: Resolution
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-misc/asterisk-1.2.13"