Symantec Security Advisory

SYM06-024

13 Dec, 2006

Symantec Veritas NetBackup (tm):  Vulnerabilities in NetBackup Server and Clients

Revision History
None

Severity
High (very configuration-dependent)
Symantec Security Advisory



NOTE:  In recommended installations, Symantec Veritas NetBackup systems should always be configured to be restricted to trusted-host access. The Veritas NetBackup Server and clients should never be exposed external to the network.  The servers and clients could still be potentially susceptible to an insider-based attack however; this recommended configuration greatly reduces the risk from unauthorized remote access through external, unauthenticated vectors.
 

Remote Access	Yes
Local Access	No
Authentication Required	Yes, if properly configured to authenticate connecting hosts and/or only accept connections from trusted / authorized hosts
Exploit publicly available	No

Overview
Multiple vulnerabilities have been identified in Symantec's Veritas NetBackup Master, Media Servers and clients.   An attacker, able to access a vulnerable NetBackup host and successfully exploit these issues, could potentially cause execution of arbitrary code resulting in possible unauthorized, elevated access to the targeted system.


Product(s) Affected
 

Product	Version	Build	Platform	Solution(s)
NetBackup Enterprise Server/NetBackup Server; Server and client, and Storage Migrator	6.0	All	All	6.0_MP4
NetBackup Enterprise Server/NetBackup Server; Server and client, and Storage Migrator	5.1	All	All	5.1_MP6
NetBackup Enterprise Server/NetBackup Server; Server and client, and Storage Migrator	5.0	All	All	5.0_MP7

Details
TippingPoint (http://tippingpoint.com/) a division of 3Com, notified Symantec of two buffer overflow vulnerabilities identified in the NetBackup bpcd daemon running on Symantec Veritas NetBackup Enterprise Servers and NetBackup Server and client systems.

The overflows occur due to a failure to do proper input validation of incoming data.  A remote attacker who successfully gains network access to an affected system and successfully passes a specifically crafted packet through one of the identified vectors to this vulnerable daemon could potentially execute arbitrary code with elevated privilege on the targeted system.  

IBM Internet Security Systems (http://xforce.iss.net/) notified Symantec of an additional programming logic error in how the bpcd daemon handles incoming system commands.

NetBackup fails to properly check the logic on incoming commands.  A remote attacker who successfully gains access to the targeted system can append commands to a valid command and potentially leverage this issue to run arbitrary commands with elevated privilege on the targeted system.

Symantec Response
Symantec takes the security of our products and our customers very seriously. Symantec engineers have verified and corrected these issues in all currently supported versions of NetBackup.  

Also, during a recent, focused, internal review of supported NetBackup product versions, Symantec engineers identified additional areas that could present potential security concerns.  Symantec engineers were already in the process of preparing and testing updates for these issues and have accelerated relevant updates into the referenced Maintenance Pack releases to aid in addressing these issues.

Maintenance Pack updates are available for all supported products. The Maintenance Packs contain cumulative security-related fixes as well as additional product enhancements and technical updates.  Symantec strongly recommends customers apply the latest Maintenance Pack releases available for their supported product versions to enhance their security posture and protect against potential security threats of this nature.

Symantec knows of no exploitation of or adverse customer impact from any of the issues noted in this advisory.

The patches listed in the Solution section of the chart above for affected products are available below in the "Related Documents" section of this TechNote.

Mitigations:

Implement NetBackup Access Control (NBAC) on NetBackup Servers and Clients
NBAC provides host-based authentication and user-level authorization through Veritas Security Services (VxSS) at both the server and the client to ensure communications are with a trusted host.


Implement Trusted-Host access through configuration files

Daemons associated with Veritas NetBackup services provide Trusted-Host access through the appropriate configuration files. Some of the services allow access by default while others deny access by default depending on the functionality of the service.  Customers should follow the documentation provided for each service to ensure they have implemented a trusted-host relationship appropriate for their network.

The vmd, oprd and robotic daemons derive access control from the vm.conf file which allows access by default if there is no SERVER entry entered.

Using an appropriate text editor, configure vm.conf's  "SERVER=<hostname>"  for allowed host entries. Once a "SERVER=<hostname>" list is compiled, the associated daemons will ONLY trust and allow hosts annotated in vm.conf.  Any malicious user or attacker would have to have either authorized access to or gain unauthorized access to one of the trusted-hosts to attempt attacks against a targeted server.

All other daemons associated with Veritas NetBackup derive access control from the NetBackup configuration which denies access by default.
Edit the configuration using "host properties" in the GUI to allow only those hosts that require access to associated NetBackup services. Any malicious user or attacker would have to have either authorized access to or gain unauthorized access to one of the trusted-hosts to attempt attacks against a targeted server.


Best Practices
As part of normal best practices, Symantec strongly recommends:

CVE
The Common Vulnerabilities and Exposures (CVE) initiative has assigned CVE Candidate numbers to these issues.
CVE Candidates CVE-2006-6222 and CVE-2006-5822 are assigned to the bpcd daemon buffer overflow issues identified by 3Com ZDI.
CVE Candidate CVE-2006-4902 is assigned to the bpcd daemon programming logic error identified by ISS.
These issues are candidates for inclusion in the CVE list (http://cve.mitre.org), which standardizes names for security problems.

Credit:
Symantec would like to thank Sebastian Apelt working with TippingPoint and the
Zero Day Initiative (http://www.zerodayintiative.com) for reporting the issues referenced in CVE-2006-6222 and CVE-2006-5822 and providing full coordination while Symantec resolved them.

Symantec would also like to thank Paul Metha, a member of IBM Internet Security System's X-Force Research Team, for reporting the issue referenced in CVE-2006-4902 and providing full coordination while Symantec resolved it.