ACROS Security: Buffer Overflow In EMC (previously Dantz) Retroclient Service

Type securityvulns
Reporter Securityvulns
Modified 2006-05-23T00:00:00




========================================================================= ACROS Security Problem Report #2006-05-17-1

ASPR #2006-05-17-1: Buffer Overflow In Retroclient Service

Document ID: ASPR #2006-05-17-1-PUB Vendor: EMC ( Target: Retrospect 7.5 Client for Windows ( Impact: A buffer overflow vulnerability in Retroclient service can be exploited to crash Retrospect clients in the network. Severity: Medium Status: Official patch available Discovered by: Luka Treiber of ACROS Security

Current version

We would like to acknowledge Eric Baize and Jamie Albertson from EMC for extremely diligent and professional handling of the identified vulnerability.


A buffer overflow vulnerability in Retroclient service can be exploited to crash Retrospect clients in the network. This enables an attacker to easily disable the backup process throughout an organization.

Product Coverage

  • Retrospect 7.5 Client for Windows - affected

Older versions are likely to be affected as well.


Altering content of one of the packets sent to the client during server- client communication can result in a buffer overflow condition, which crashes the client service. Consequently, the automated backup process on the affected client no longer works. Moreover, under specific circumstances this vulnerability could be exploited for executing arbitrary code on the system running the Retrospect client. Note that access to corporate network is needed for exploiting this vulnerability as it requires an attacker to establish a network connection to a vulnerable client.

Attack Scenario:

The attacker is connected to a corporate network with his laptop. Using a port scanner, she locates machines with port 497 open, indicating the presence of Retroclient service. Using her malicious tool she mimics Retrospect server's behavior: simultaneously the tool connects to enumerated clients and sends them malicious data as described in the analysis above, which results in their crashing. In a short period of time all Retrospect clients in the network are disabled.


EMC has issued a security bulletin [1] and published a patch which fixes this issue.


  • We're not aware of any efficient workarounds for this issue.


[1] EMC Retrospect Knowledgebase


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Revision History

May 17, 2006: Initial release


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