Re: EMC Avamar: World writable cache files

[security_alert () emc com]

ESA-2013-003: EMC Avamar Client Elevation of Privilege Vulnerability

EMC Identifier: ESA-2013-003

CVE Identifier: CVE-2012-2291

Severity Rating: CVSS v2 Base Score: 6.8 (AV:L/AC:L/Au:S/C:C/I:C/A:C)
Affected products:  

•       EMC Avamar HP-UX Client 4.x, 5.x and 6.x
•       EMC Avamar Mac OS Client 4.x, 5.x and 6.x
•       EMC Avamar Plugin for Oracle 4.x, 5.x and 6.x

Note: Other Linux and Unix Avamar client systems could also be affected as a result of a support or locally-performed 
procedure that incorrectly sets the permission of the Avamar var directory (/usr/local/avamar/var or /opt/AVMRclnt/var).

Summary:  

Due to a vulnerability, described in detail below, the Avamar client leaves certain directories and files as world 
writable.  The presence of world writable directories and files may inadvertently result in elevation of privileges by 
a user who has access to the local file system. 

Details:  

The Avamar affected client process runs as root and after each backup it leaves the cache files as world readable and 
writable. While the cache files themselves do not contain sensitive information, when the parent directory is 
world-writable, the cache files could be used by an attacker to elevate the privileges when a system-level backup is 
performed.  The non-root user can create symbolic links to obtain unauthorized access to files on the affected system.

Note: This vulnerability information is currently public. EMC is not aware of any instance in which the vulnerability 
has been exploited maliciously.

Resolution:  

The following EMC Avamar product contains a resolution to this issue:

•       EMC Avamar Client Hotfix # 50184 (client version 6.1.101-89)

The Avamar client software must be upgraded by applying client hotfix #50184 (client version 6.1.101-89). This hotfix 
first requires the Avamar Server to be upgraded to 6.1.0 or newer.
If your Avamar Server is already at 6.1.0 or newer, then you can upgrade your client version to 6.1.101-89.  See 
http://solutions.emc.com/emcsolutionview.asp?id=esg135935 for detailed instructions.

If you do not wish to upgrade your client software at this time, Tthe following workaround steps must be performed to 
mitigate the risk. until the full fix is available from EMC.

For HP-UX clients:
The permissions of the /opt/AVMRclnt/var directory should be set to 0755. 
Log into the HP-UX client as the “root” user and type the following command:
chmod 0755 /opt/AVMRclnt/var

For Mac OS clients:
The permissions of the /var/avamar directory should be set to 0755. 
Log into the Mac client as the “root” user and type the following command:
chmod 0755 /var/avamar

For Oracle clients:
The following procedure only applies to clients where the directory permissions of the Avamar var directory 
(/usr/local/avamar/var or /opt/AVMRclnt/var) have been manually changed after installation of the Avamar plugin for 
Oracle:
The permissions of the /usr/local/avamar/var should be set to 0775 with the group ownership set to the oracle group. 
Log into the Oracle client as the “root” user and type either of the following pairs of commands:

On Linux and Unix Oracle clients other than Solaris and HP-UX:

chmod 0775 /usr/local/avamar/var
chgrp oracle /usr/local/avamar/var

On Solaris and HP-UX Oracle clients:

chmod 0775 /opt/AVMRclnt/var
chgrp oracle /opt/AVMRclnt/var

Other Avamar clients:

 Verify that the permissions of the Avamar var directory (/usr/local/avamar/var or /opt/AVMRclnt/var) on Linux and Unix 
clients are not modified as a result of a support or locally-performed procedure. The permissions should be set to 0755.


If you have any questions or concerns about running the above commands please contact EMC Technical Support at 
http://www.emc.com/contact

[The following is standard text included in all security advisories.  Please do not change or delete.]

Read and use the information in this EMC Security Advisory to assist in avoiding any situation that might arise from 
the problems described herein. If you have any questions regarding this product alert, contact EMC Software Technical 
Support at 1-877-534-2867.

For an explanation of Severity Ratings, refer to EMC Knowledgebase solution emc218831. EMC recommends all customers 
take into account both the base score and any relevant temporal and environmental scores which may impact the potential 
severity associated with particular security vulnerability.

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