Computer Associates Brightstor ARCserve Mediasvr.exe String Handling Overflow

Notification Type: IBM Internet Security Systems Protection Advisory
Notification Date: Jan 11, 2007
Notification Version: 1.2

Computer Associates Brightstor ARCserve Mediasvr.exe String Handling Overflow

Public disclosure/
In the wild date:
Jan 11, 2007 (vuln)


Description: IBM Internet Security Systems X-Force has discovered two remotely exploitable vulnerabilities in CA Brightstor ARCserve mediasvr.exe service. The second vulnerability, XFID 29344, is a stack based overflow in the RPC interface that can be triggered over SUNRPC. By sending a specially crafted packet, it is possible to trigger the stack-based buffer overflow ultimately resulting in remote code execution. ISS products have provided protection for this vulnerability since Nov. 14, 2006.


ISS Coverage

Product Content Version
Network Sensor 7.0
Proventia A
Proventia IPS (G/GX) prior to Firmware Version 1.2
Server Sensor 7.0
Proventia IPS (G/GX) Firmware Version 1.2 or
Proventia Multifunction Appliance
Proventia Server (Linux)
Proventia Server (Windows) 1.0.914.1910
Proventia Desktop 8.0.x.1910
RealSecure Desktop 7.0 EPW
BlackICE PC Protection 3.6 CPW
Propagation Techniques ISS Protection Available
Remote exploit Sunrpc_BackupProduct_String_Overflow Nov 14, 2006
Detection Techniques ISS Protection Available
vulnerability assessment tbd tbd 

Detailed Description

Business Impact: Compromise of networks and machines using affected versions of Brightstor ARCserve may lead to exposure of confidential information, loss of productivity, and further network compromise. An attacker does not need to entice any kind of user interaction to trigger this vulnerability. Successful exploitation could grant an attacker administrative privileges on the target machine.
CVSS: Base Score: 10.0
  Access Vector: Remote 
Access Complexity: Low 
Authentication: Not Required 
Confidentiality Impact: Complete 
Integrity Impact: Complete 
Availability Impact: Complete 
Impact Bias: Normal 
Adjusted Temporal Score: 7.4 
  Exploitability: Unproven 
Remediation Level: Official Fix 
Report Confidence: Confirmed 
Affected Products:

BrightStor Products:
- BrightStor ARCserve Backup r11.5
- BrightStor ARCserve Backup r11.1
- BrightStor ARCserve Backup for Windows r11
- BrightStor Enterprise Backup r10.5
- BrightStor ARCserve Backup v9.01

CA Protection Suites r2:
- CA Server Protection Suite r2
- CA Business Protection Suite r2
- CA Business Protection Suite for Microsoft Small Business Server Standard Edition r2
- CA Business Protection Suite for Microsoft Small Business Server Premium Edition r2

Remedy: Patches for this issue were available Jan. 11, 2007.  Apply the appropriate fix for your system (QO84983, QO84984, QI82917, QO84986, or QO84985), available from the CA SupportConnect Web site. See References.
Technical Description:

CA Brightstor ARCserve is a cross platform backup and recovery solution for small to medium sized businesses. BrightStor ARCserve Backup protects and helps ensure the availability of critical applications and data. Brightstor ARCserve is widely deployed in enterprise environments.

The vulnerability exists in the SUNRPC interface where a user definable length is used for several strncpy()’s to static size stack buffers. The user definable string data is then copied to the stack buffer potentially causing an overflow.

This vulnerability does not require any user interaction to be exploited.

An exploit for this vulnerability is very reliable.

Credit: This vulnerability was researched and discovered by Paul Mehta a member of IBM Internet Security Systems X-Force.


CA: CA SupportConnect Web site, Important Security Notice for BrightStor ARCserve Backup

Revision History

1.0 Initial advisory.
1.1 Added information about patches and a link to Computer Associate's advisories.
1.2 Corrected two typos in the description.

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