Solved

Cisco buffer overflow vulnerability

Posted on 2016-07-17
3
23 Views
Last Modified: 2016-07-18
Got an IPS alert that says " Telnet: Cisco Buffer Overflow Vulnerability (High)
Network Security Platform has detected a  "High (9)" attack.  
Attack type: Signature: telnet-cmd-too-long"

Can I correctly say:
a) if we don't have telnet service enabled on all our Cisco devices, then we're not
    vulnerable (even if telnet is enabled on some other legacy systems) ?
b) this only affects Cisco 676/677 devices, so if we don't have these devices in
     our environment, then we're not vulnerable

If I'm mistaken to make above 2 statements, do elaborate & explain
0
Comment
Question by:sunhux
  • 2
3 Comments
 

Author Comment

by:sunhux
ID: 41715039
If we have PCs that do telnet to our AS400 servers, would this activity
trigger such alerts?
0
 

Author Comment

by:sunhux
ID: 41715040
Correction:
> Cisco 676/677
   should be
Cisco 678/677

The other question is we don't always get this alert, so is it likely that this is triggered
by telnet  from a PC to the AS400 host?  Or someone issued a different telnet access
this time round?
0
 
LVL 34

Accepted Solution

by:
Gary Patterson earned 500 total points
ID: 41716192
Your IPS observed some telnet traffic that matched the signature for "Telnet: Cisco Buffer Overflow Vulnerability".  IPS thinks there is a high probability that the traffic it saw was an attempt at a buffer overflow attack against whatever the target system was.

Is it possible it was a false alarm?  Yes.  But you shopuld assume it is a real attack until you can prove otherwise.  We'd need to know more, like see the specific packets involved to determine if it was a real attack or a false alarm.

What host was destination of this attack?  Was it your AS/400?  What was the source address of the problem packets?  Was it a host within your network, or an unknown outside host?

If you don't use Telnet anywhere in your network, then you don't have to worry about this attack or any other Telnet-related attacks.  But attackers don't tend to stop with just Telnet attacks - they tend to attack every open port or service they find - hoping to discover a vulnerable service.
0

Featured Post

Efficient way to get backups off site to Azure

This user guide provides instructions on how to deploy and configure both a StoneFly Scale Out NAS Enterprise Cloud Drive virtual machine and Veeam Cloud Connect in the Microsoft Azure Cloud.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

By this time the large percentage of day-to-day transactions have shifted to mobile banking; here are some overriding areas QAs must investigate while testing mobile banking apps.  
Find out what Office 365 Transport Rules are, how they work and their limitations managing Office 365 signatures.
Sending a Secure fax is easy with eFax Corporate (http://www.enterprise.efax.com). First, Just open a new email message.  In the To field, type your recipient's fax number @efaxsend.com. You can even send a secure international fax — just include t…
When you create an app prototype with Adobe XD, you can insert system screens -- sharing or Control Center, for example -- with just a few clicks. This video shows you how. You can take the full course on Experts Exchange at http://bit.ly/XDcourse.

929 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

9 Experts available now in Live!

Get 1:1 Help Now