SSH Password attacks using domain name elements as userid
A reader (Thanks Jim!) mentioned earlier today that his SSH logs were showing access attempts utilising elements of the reverse DNS name of the IP address being accessed. For example using isc.sans.org results in the userids isc, sans and org. This may be cause a number of hosting providers use the domain name itself as the userid for shell access for customers. In light of the breach at dreamhost earlier this week http://blog.dreamhost.com/2012/01/21/security-update/ this may be what is going on.
If you are noticing the same in your logs and you can share some log lines please send some in as I'd be interested in taking a peek.
Mark H
CISCO Ironport C & M Series telnet vulnerability
In case you missed it there is a vulnerability in the CISCO Ironport telnet service. Details can be found here http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20120126-ironport
To mitigate the risk (if you can't upgrade just yet) is to switch off telnet on the device and use SSH to manage it instead.
Mark H
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