View source for KB 119

===Vulnerabilities in older versions of CBOS for Cisco 675/678 routers===
 Article:119
 Created:2001-05-28 14:44:32
 Categories:
   DSL
   Security

====Question or Symptom====
Should I upgrade the version of CBOS on my Cisco 675/678 router?


====Resolution====
Here are notes from Cisco about speicfic vulnerabilities in CBOS for the
Cisco 600 series routers.  It is recommended that you upgrade to the
latest version if you are concerned about these issues.
  
------------------------------------------------------------------------------
Summary
  
Multiple vulnerabilities have been identified and fixed in CBOS, an 
operating system for the Cisco 600 family of routers.
  
Cisco CBOS Software contains a flaw that permits the successful 
prediction of TCP Initial Sequence Numbers. It only affects the
security of TCP connections that originate or terminate on the 
affected Cisco device itself; it does not apply to TCP traffic 
forwarded through the affected device in transit between two other hosts.
  
This vulnerability is documented as Cisco bug ID CSCds16078.
  
A Cisco 600 router may stop passing the traffic and responding to 
the console when an ECHO REQUEST packet with the record
route option is routed through it.
  
This vulnerability is documented as Cisco bug ID CSCds30150.
  
Passwords, exec and enable, are stored in the cleartext in the NVRAM.
  
This vulnerability is documented as Cisco bug ID CSCdt04882.
  
When multiple, large ECHO REPLY packets are routed through an 
affected Cisco 600 router, it will enter the ROMMON mode and
stop passing any further traffic.
  
This vulnerability is documented as Cisco bug ID CSCds74567.
  
The following releases of CBOS are containing all of mentioned 
vulnerabilities: 2.0.1, 2.1.0, 2.1.0a, 2.2.0, 2.2.1, 2.2.1a, 2.3, 
2.3.2, 2.3.5, 2.3.7
and 2.3.8.
  
These vulnerabilities are fixed in the following CBOS releases: 
2.3.9, 2.4.1 and 2.4.2. Customers are urged to upgrade to releases 
that are not vulnerable as shown in detail in the section Software
Versions and Fixes below.
------------------------------------------------------------------------------

====Related URLS====
  http://www.cisco.com/warp/public/707/CBOS-multiple2-pub.html


====Related KB articles====
  [[KB 81]] How do I configure my Cisco 675 or 678 for Megabit service?

  [[KB 94]] How does one set up port forwarding on the Cisco 675 router?

  [[KB 95]] How does one change the internal IP address of the Cisco 675 router?

  [[KB 104]] How do I set up a Cisco 675 or 678 router to use a routed subnet
     (instead of NAT)?

  [[KB 113]] Is the Cisco 678 configured the same as the 675 for QWest DSL?