Advisory Details

April 20th, 2011

Nortel CS1000 Communications Server Remote Denial of Service Vulnerability

ZDI-11-141
ZDI-CAN-950

CVE ID
CVSS SCORE 10.0, AV:N/AC:L/Au:N/C:C/I:C/A:C
AFFECTED VENDORS Nortel
AFFECTED PRODUCTS CS1000 Communications Server
TREND MICRO CUSTOMER PROTECTION Trend Micro TippingPoint IPS customers are protected against this vulnerability by Digital Vaccine protection filter ID ['11103']. For further product information on the TippingPoint IPS: http://www.tippingpoint.com
VULNERABILITY DETAILS

This vulnerability allows remote attackers to create a denial of service condition on vulnerable installations of Nortel CS1000 Communication Server. Authentication is not required to exploit this vulnerability.

The specific flaw exists within the process listening on UDP port 5100. When parsing a request, it takes the size and subtracts 2. This can be abused to cause the integer to wrap negatively and subsequently cause the process to crash while copying memory. This can be abused by a remote attacker to crash the PBX server.

ADDITIONAL DETAILS Nortel has issued an update to correct this vulnerability. More details can be found at:
https://support.avaya.com/css/P8/documents/100133768
DISCLOSURE TIMELINE
  • 2010-09-24 - Vulnerability reported to vendor
  • 2011-04-20 - Coordinated public release of advisory
CREDIT Anonymous
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