This issue can affect all Junos devices with J-Web enabled.
An insufficient validation vulnerability in J-Web can allow an authenticated user to execute arbitrary commands. This may allow a user with low privilege (such as read only access) to get complete administrative access. This scope of this vulnerability is limited to only those users with valid, authenticated login credentials.
Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
No other Juniper Networks products or platforms are affected by this issue.
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-D15, 12.1X45-D10, 12.2R3, 12.3R1, and all subsequent releases (i.e. all releases built after 12.3R1).
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 826518 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.
Disable J-Web, or limit access to only trusted hosts.
Acknowledgement The Juniper SIRT would like to acknowledge and thank Phil from Sense of Security Labs for reporting this vulnerability.
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.