2015-01 Security Bulletin: Junos: Malformed BGP FlowSpec prefix triggers rpd crash (CVE-2014-6386)

Product Affected:This issue can affect any product or platform running Junos OS with BGP FlowSpec enabled.

Problem:Receipt of a malformed BGP FlowSpec prefix may cause the router to trigger an assert (program​​matic crash) when detecting a certain specification violation. Rather than simply flagging, logging, and/or dropping the packet, the routing process daemon (rpd) will crash and restart.​This issue was found during negative protocol testing and has not been seen in a production network.Juniper SIRT is not aware of any malicious exploitation of this vulnerability.No other Juniper Networks products or platforms are affected by this issue.​This issue has been assigned CVE-2014-6386.

Solution:The program assert has been replaced with ​standard BGP error handling logic, allowing rpd to continue to function upon receipt of the malformed BGP FlowSpec prefix.​The following software releases have been updated to resolve this specific issue: Junos OS 11.4R8, 12.1X44-D35, 12.1X45-D25, 12.1X46-D20, 12.1X47-D10, 12.2R9, 12.3R2-S3, 12.3R3, 13.1R4, 13.2R1, and all subsequent releases.This issue is being tracked as PR 878438 and is visible on the Customer Support website.KB16765 – “In which releases are vulnerabilities fixed?” describes which release vulnerabilities are fixed as per our End of Engineering and End of Life support policies.

Workaround:Only configure the FlowSpec NLRI to a known trusted BGP peer. Using MD5 authentication is also a good security practice.In addition to the recommendations listed above, it is good security practice to limit the exploitable attack surface of critical infrastructure networking equipment. Use access lists or firewall filters to limit access to the router via FlowSpec only from trusted, administrative networks or hosts.

Implementation: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. Modification History: 2015-01-14: Initial publication

Related Links: CVSS Score:7.1 (AV:N/AC:M/Au:N/C:N/I:N/A:C)

Risk Level:High

Risk Assessment:Information for how Juniper Networks uses CVSS can be found at KB 16446 “Common Vulnerability Scoring System (CVSS) and Juniper’s Security Advisories.”

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