Product Affected

This issue can affect any Junos device with Proxy ARP enabled, running one of the affected releases listed below.
High
7.8 (AV:N/AC:L/Au:N/C:N/I:N/A:C)

Problem


Certain specific types of ARP packets can trigger a kernel crash leading to a Denial of Service in Junos when Proxy ARP is enabled.

This issue was introduced as a regression and only affects the following versions of Junos: 10.4R11-10.4R12, 11.4R5-11.4R6, 12.1R3-12.1R4. This issue specifically does not affect the Junos 11.4X27 MX BBE and 12.1X44 SRX special releases.

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


All Junos OS software releases built on or after 2013-02-28 have fixed this specific issue. Releases containing the fix specifically include: 10.4R13, 11.4R7, 12.1R5, 12.1X44-D10, and all subsequent releases (i.e. all releases built after 12.1X44-D10).

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 825577 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


If Proxy ARP is not required, disabling Proxy ARP will completely mitigate this issue. Since this issue requires the reception of an ARP packet, the attack surface is limited to the local broadcast domain.

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