Public Vulnerability Reports

CA BrightStor ARCserve Backup v11 Discovery Service Remote Buffer Overflow

02.09.05

BACKGROUND

BrightStor ARCserve Backup for Windows delivers backup and restore
protection for all Windows server systems as well as Windows, Linux,
Mac OS X and UNIX client environments.

http://www3.ca.com/Solutions/ProductFamily.asp?ID=115

DESCRIPTION

Remote exploitation of a buffer overflow vulnerability in Computer
Associates International Inc's BrightStor ARCserve Backup v11 Discovery
Service may allow execution of arbitrary code.

The BrightStor software will automatically detect other BrightStor
(ARCserve) servers on the local network. It does this by sending UDP
probe messages to the broadcast address on the network. Each system
running the BrightStor software listens for these probes and replies
back to IP address embedded in the data of the packet. The Discovery
service listens on UDP port 41524 for these probe requests.

ANALYSIS

When a UDP probe is received by the Discovery Service, a stack overflow
can occur if the data is larger than the temporary buffer. The
recvfrom() call made by the service accepts up to 4096 bytes, however
the buffer it is copied to is slightly less than 1000 bytes. The return
address can be overwritten by sending a message that is at least 967
bytes long. As the service runs as 'Local System', exploitation of  this
vulnerability allows running arbitrary code with superuser  privileges.

DETECTION

Computer Associates BrightStor ARCserve Backup v11 (Win32) has been
confirmed vulnerable.

WORKAROUND

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

VENDOR RESPONSE

http://supportconnectw.ca.com/public/enews/BrightStor/brigcurrent.asp

The following vendor patches have been made available:

BrightStor ARCserve Backup r11.1 for Windows - All Languages -
http://supportconnect.ca.com/sc/redir.jsp?reqPage=search&searchID=QO62769

BrightStor ARCserve Backup r11.0 for Windows - All Languages -
http://supportconnect.ca.com/sc/redir.jsp?reqPage=search&searchID=QO62768

BrightStor Enterprise Backup v10.5 for Windows -
http://supportconnect.ca.com/sc/redir.jsp?reqPage=search&searchID=QO62770

BrightStor Enterprise Backup v10.0 for Windows -
http://supportconnect.ca.com/sc/redir.jsp?reqPage=search&searchID=QO62771

BrightStor ARCserve Backup v9.01 for Windows - All Languages -
http://supportconnect.ca.com/sc/redir.jsp?reqPage=search&searchID=QO62767

BrightStor ARCserve 2000 Backup for Windows (Japanese Only) -
http://supportconnect.ca.com/sc/redir.jsp?reqPage=search&searchID=QO62766

BrightStor ARCserve Backup r11.1 for NetWare
http://supportconnect.ca.com/sc/redir.jsp?reqPage=search&searchID=QO62936

BrightStor ARCserve Backup v9 for NetWare
http://supportconnect.ca.com/sc/redir.jsp?reqPage=search&searchID=QO62772

BrightStor ARCserve Backup r11.1 for Windows - 64 Bit Edition -
http://supportconnect.ca.com/sc/redir.jsp?reqPage=search&searchID=QO62990

BrightStor ARCserve Backup r11.0 for Windows - 64 Bit Edition -
http://supportconnect.ca.com/sc/redir.jsp?reqPage=search&searchID=QO62989

BrightStor Enterprise Backup v10.5 for Windows - 64 Bit Edition -
http://supportconnect.ca.com/sc/redir.jsp?reqPage=search&searchID=QO62991

BrightStor ARCserve Backup v9.01 for Windows - 64 Bit Edition -
http://supportconnect.ca.com/sc/redir.jsp?reqPage=search&searchID=QO62987

CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
names CAN-2005-0260 to these issues. This is a candidate for inclusion
in the CVE list (http://cve.mitre.org), which standardizes names for
security problems.

DISCLOSURE TIMELINE

11/12/2004   Initial vendor notification
11/15/2004   Initial vendor response
02/09/2005   Public disclosure

CREDIT

This vulnerability was discovered independently by two contributors,
one of whom is Patrik Karlsson. The other wishes to remain anonymous.

Get paid for vulnerability research
http://www.idefense.com/poi/teams/vcp.jsp

LEGAL NOTICES

Copyright © 2005 Verisign, Inc.

Permission is granted for the redistribution of this alert
electronically. It may not be edited in any way without the express
written consent of iDEFENSE. If you wish to reprint the whole or any
part of this alert in any other medium other than electronically, please
email customerservice@idefense.com for permission.

Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
of the information constitutes acceptance for use in an AS IS condition.
There are no warranties with regard to this information. Neither the
author nor the publisher accepts any liability for any direct, indirect,
or consequential loss or damage arising from use of, or reliance on,
this information.