Software Engineering Institute

BrightStor ARCserve Backup is a backup and data retention tool that integrates with other BrightStor Data Availability and BrightStor Storage Management solutions. A vulnerability exists in Mediasrv.exe which is a component of BrightStor ARCserve Backup Tape Engine. The Tape Engine features allow BrightStor ARCserve Backup products to use tape drives for storage.

This vulnerability may be exploited by sending a specially crafted RPC request to a vulnerable system. According to Shirkdog Security Advisory SHK-004:
There seems to be an design error in the handling of RPC data with xdr procedures across several .dll's imported by Mediasvr.exe.

Note that the vulnerable software may be running on any machines that have BrightStor ARCserve Backup products installed.

We are aware of publicly available exploit code for this vulnerability.

A remote, unauthenticated attacker may be able to execute arbitrary code.

Update
BrightStor has released patches to address this issue. See BrightStor ARCserve Backup Media Server Security Notice for more details.

Disable mediasvr.exe

Computer Associates recommends the following temporary workaround to mitigate the vulnerability:

1) Rename the "mediasvr.exe" file to a non-functional file name,
such as "mediasvc.exe.disable".

2) Then restart the CA BrightStor Tape Engine service.

Note that this will disable the product's command line functionality.