2015-07 Security Bulletin: Junos: BFD daemon crash upon receipt of crafted BFD packet (CVE-2015-5362)

Product Affected:This issue can affect any product or platform running Junos OS.

Problem:Receipt of a specially crafted BFD packet can cause the BFD daemon (bfdd) to crash and restart, generating a bfdd core file. Continuous receipt of crafted BFD packets could result in an extended BFD outage, or in extreme cases could lead to remote code execution. The issue can affect all configurations and topologies utilizing BFD including: single-hop and multi-hop BFD, centralized and distributed mode BFD, micro-BFD and LSP BFD. Note that the bfdd crash can be triggered by a crafted BFD packet even if BFD is not enabled on the interface. See Workaround section below for instructions to disable BFD globally. 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-2015-5362.

Solution:The following software releases have been updated to resolve this specific issue: Junos OS 12.1X44-D50, 12.1X46-D35, 12.1X47-D25, 12.3R10, 12.3X48-D15, 13.2R8, 13.3R6, 14.1R5, 14.1X50-D85, 14.1X55-D20, 14.2R3, 15.1R1, 15.1X49-D10, and all subsequent releases. This issue is being tracked as PR 1004482 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:Use access lists or firewall filters on input interfaces or the control plane (lo0) to limit access to the router via BFD only from trusted hosts. If BFD is not used at all, the BFD daemon (bfdd) can be disabled via the following configuration change: ‘set system processes neighbor-liveness disable’ Additionally, according to Section 6 of RFC 5883: “… multihop paths expose BFD to spoofing. As the number of hops increases, the exposure to attack grows. As such, implementations of BFD should utilize cryptographic authentication over multihop paths to help mitigate denial-of-service attacks.”

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: 2015-07-08: Initial publication

Related Links: CVSS Score:CVSSv2 Base Score: 9.3 (AV:N/AC:M/Au:N/C:C/I:C/A:C)

Risk Level:Critical

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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