Public Vulnerability Reports

Apple Darwin Streaming Server DESCRIBE Null Byte Denial of Service Vulnerability



Darwin Streaming Server is an open source version of Apple's QuickTime
Streaming Server technology that allows you to send streaming media to
clients across the Internet using the industry standard RTP and RTSP


Remote exploitation of an input validation vulnerability in Apple
Computer Inc.'s Darwin Streaming Server allows attackers to cause a
denial of service condition. The vulnerability specifically occurs due
to insufficient sanity checking on arguments to DESCRIBE requests. A
remote attacker can send a request for a location containing a null byte
to cause a denial of service condition resulting in the following

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1026 (LWP 9648)]
0x4207ac9e in chunk_free () from /lib/i686/
(gdb) bt
#0 0x4207ac9e in chunk_free () from /lib/i686/
#1 0x4207ac24 in free () from /lib/i686/
#2 0x08096406 in FindOrCreateSession (inPath=0x408caf3c,
   inParams=0x81746f0, inData=0x0, isPush=0, foundSessionPtr=0x0) at


Successful exploitation allows any remote unauthenticated attacker to
crash the targeted server, thereby preventing legitimate users from
accessing streamed content.


iDEFENSE has confirmed the existence of this vulnerability in Darwin
Streaming Server 5.0.1. It is suspected that earlier versions are also


Employ firewalls, access control lists or other TCP/UDP restriction
mechanisms to limit access to systems and services.


The following updates are available from Apple Downloads
( to address this

Mac OS X 10.2.8 Client

Mac OS X 10.2.8 Server

Mac OS X 10.3.6 Client

Mac OS X 10.3.6 Server


The Common Vulnerabilities and Exposures (CVE) project has assigned the
names CAN-2004-1123 to these issues. This is a candidate for inclusion
in the CVE list (, which standardizes names for
security problems.


09/10/2004    Initial vendor notification
09/15/2004    Initial vendor response
12/03/2004    Coordinated public disclosure


The discoverer of this vulnerability wishes to remain anonymous.

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Copyright © 2004 Verisign, Inc.

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