Product Affected

This issue can affect all releases of Junos, starting with Junos OS 10.0, that support the flow-specification NLRI message, and have the 'flow' configuration option enabled.
Medium
6.3 (AV:N/AC:M/Au:S/C:N/I:N/A:C)

Problem


Receipt of a BGP UPDATE message containing a crafted flow specification NLRI (RFC 5575) may cause RPD to crash. The update creates an invalid inetflow prefix which causes the RPD process to allocate memory until it reaches its assigned memory limit. After trying to exceed the process memory limit, RPD will crash and restart. The system recovers after the crash, however a constant stream of malformed updates could cause an extended outage.

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

No other Juniper Networks products or platforms are affected by this issue.

Solution


RPD now logs an error when receiving the malformed update and avoids the memory allocation loop.

All Junos OS software releases built on or after 2012-10-05 have fixed this specific issue. Releases containing the fix specifically include: 10.0S28, 10.4R11, 11.4R5, 12.1R3, 12.1X44-D20, 12.1X45-D10, 12.2R1 and all subsequent releases (i.e. all releases built after 12.2R1).

Customers can confirm the build date of any Junos OS release by issuing the command 'show version detail'.

This issue is being tracked as PR 734453 and is visible on the Customer Support website.

KB16765 [juniper.net] - "In which releases are vulnerabilities fixed?" describes which release vulnerabilities are fixed as per our End of Engineering and End of Life support policies.


How to obtain fixed software:

Security vulnerabilities in Junos are fixed in the next available Maintenance Release of each supported Junos version. In some cases, a Maintenance Release is not planned to be available in an appropriate time-frame. For these cases, Service Releases are made available in order to be more timely. Security Advisory and Security Notices will indicate which Maintenance and Service Releases contain fixes for the issues described. Upon request to JTAC, customers will be provided download instructions for a Service Release. Although Juniper does not provide formal Release Note documentation for a Service Release, a list of "PRs fixed" can be provided on request.

Workaround

Disable the propagation of flow-specification NLRI messages via BGP by removing the 'flow' configuration option from 'protocols bgp ... family inet'. For example: 

user@JUNOS# edit protocols bgp family inet
{master:member0-re0}[edit protocols bgp family inet]
 
user@JUNOS# delete flow
  {master:member0-re0}[edit protocols bgp family inet]

Severity Assessment

Information for how Juniper Networks uses CVSS can be found at KB 16446 [juniper.net] "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."

Related Information

Acknowledgements