Preview Tool

Cisco Bug: CSCtd67026 - SSL/TLS Vulnerable to a Memory Exhaustion DOS Attack

Last Modified

Aug 06, 2018

Products (1)

  • Cisco IPS 4200 Series Sensors

Known Affected Releases

6.0(6) 6.1(2) 6.2(2)E 7.0(1)B 7.1(0)B118

Description (partial)


The IPS's SSL/TLS implementation is vulnerable to a memory exhaustion denial-of-service attack. This 
vulnerability allows attackers with an established SSL/TLS connection to the IPS to send traffic over this connection 
that will eventually exhaust the IPS's system memory. IPS software can become unstable once the memory is 
exhausted. This may cause the IPS to go into bypass, become unresponsive or automatically reboot.

The main way to determine whether this is occurring is to open IDM/IME and view the usage information for the 
IPS's management interface along side the IPS's memory usage information. The IPS may be 
experiencing an attack if both are increasing interface traffic and memory usage are steadily increasing at a similar 


This vulnerability is present in IPS versions 006.000(006) 006.001(002) 06.2(02) 07.0(01) and earlier versions of the 
same major/minor releases.

The IPS is only vulnerable to attackers whose IP addresses are on the IPS's access list. The attackers do not 
have to be authenticated to exploit this vulnerability.
Bug details contain sensitive information and therefore require a account to be viewed.

Bug Details Include

  • Full Description (including symptoms, conditions and workarounds)
  • Status
  • Severity
  • Known Fixed Releases
  • Related Community Discussions
  • Number of Related Support Cases
Bug information is viewable for customers and partners who have a service contract. Registered users can view up to 200 bugs per month without a service contract.