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CA-2003-23 RPCSS Vulnerabilities in Microsoft Windows
release date: September 10, 2003
Last revised: --
revision history can be found at the end of this file.
Windows NT Workstation 4.0
* Microsoft Windows NT Server 4.0
* Microsoft Windows NT Server 4.0, Terminal Server Edition
* Microsoft Windows 2000
* Microsoft Windows XP
* Microsoft Windows Server 2003
has published a bulletin describing three vulnerabilities
that affect numerous versions of Microsoft Windows. Two of these
vulnerabilities are remotely exploitable buffer overflows that may
allow an attacker to execute arbitrary code with system privileges.
The third vulnerability may allow a remote attacker to cause a denial
RPCSS Service is responsible for managing Remote
Procedure Call (RPC) messages. There are two buffer overflow
vulnerabilities in the RPCSS service, which is enabled by default on
many versions of Microsoft Windows. These buffer overflows occur in
sections of code that handle DCOM activation messages sent to the
is tracking these vulnerabilities as VU#483492 and
VU#254236, which correspond to CVE candidates CAN-2003-0715 and
CAN-2003-0528, respectively. The buffer overflows discussed in this
advisory are different than those discussed in previous advisories.
has also published information regarding a denial-of-service
vulnerability in the RPCSS service. This vulnerability only affects
Microsoft Windows 2000 systems.
is tracking this vulnerability as VU#326746, which
corresponds to CVE candidate CAN-2003-0605. This vulnerability was
previously discussed in CA-2003-19.
either of the buffer overflow vulnerabilities, remote
attackers may be able to execute arbitrary code with Local System
the denial-of-service vulnerability, remote attackers
may be able to disrupt the RPCSS service. This may result in general
system instability and require a reboot.
patch from Microsoft
has published Microsoft Security Bulletin MS03-039 to
address this vulnerability. For more information, please see
to and from common Microsoft RPC ports
interim measure, users can reduce the chance of successful
exploitation by blocking traffic to and from well-known Microsoft RPC
* Port 135 (tcp/udp)
* Port 137 (udp)
* Port 138 (udp)
* Port 139 (tcp)
* Port 445 (tcp/udp)
* Port 593 (tcp)
compromised hosts from contacting other vulnerable hosts,
the CERT/CC recommends that system administrators filter the ports
listed above for both incoming and outgoing traffic.
COM Internet Services and RPC over HTTP
Services (CIS) is an optional component that allows RPC
messages to be tunneled over HTTP ports 80 and 443. As an interim
measure, sites that use CIS may wish to disable it as an alternative
to blocking traffic to and from ports 80 and 443.
DCOM as described in MS03-039 and Microsoft Knowledge Base
was written by Jeffrey P. Lanza and is based upon the
information in MS03-039.
is available from:
Phone: +1 412-268-7090 (24-hour hotline)
Fax: +1 412-268-6989
CERT Coordination Center
Software Engineering Institute
Carnegie Mellon University
Pittsburgh PA 15213-3890
personnel answer the hotline 08:00-17:00 EST(GMT-5) /
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2003 Carnegie Mellon University.
Sep 10, 2003: Initial release
Version: PGP 6.5.8
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