Cisco has warned of a default Secure Shell vulnerability in three of its virtual applications.
The flaw could allow attackers to decrypt traffic exchanged in the services, and has been detailed in a Cisco security advisory.
It affects Cisco’s Web Security Virtual Appliance (SMAv), Email Security Virtual Appliance and Security Management Virtual Appliance, which are already commercially available.
Cisco said that it “is not aware of any public announcements or malicious use of the vulnerabilities”, but warned that attackers who got hold of the private keys could decrypt communications with a man-in-the-middle attack.
The default private encryption keys were preinstalled on all three of the products, a move which is considered bad security practice.
“Successfully exploiting this vulnerability on Cisco SMAv allows an attacker to decrypt communication toward SMAv, impersonate SMAv, and send altered data to a configured content appliance,” the advisory said.
“An attacker can exploit this vulnerability on a communication link toward any content security appliance that was ever managed by any SMAv.”
Cisco has released a patch which deletes the preinstalled SSH keys and explains how customers can correct the problem.
The Cisco-sa-20150625-ironport SSH Keys Vulnerability Fix comes as part of several product upgrades, and must be manually installed from a command line interface.
Cisco’s advisory said that the patch is not required for physical hardware appliances, or for virtual appliance downloads or upgrades after 25 June.
Cisco revealed details of a new point of sale attack earlier this year that could part firms from money and customers from personal data.
The threat, called PoSeidon by the Cisco team, came at a time when eyes were on security breaches at firms like Target.
Cisco said in a blog post that PoSeidon is a threat that has the ability to breach machines and scrape them for credit card information.
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