Product Affected

This is a zero day issue which affects all JUNOS routers with the J-Web browser-based management interface enabled.
Medium
5.0 (AV:N/AC:L/Au:N/C:N/I:P/A:N/E:F/RL:U/RC:C)

Problem


ProCheckUp has reported a Cross-Site Scripting vulnerability on Juniper routers running with the JUNOS web interface, J-Web, enabled. The reporter found that by making a malformed request to the J-Web interface, vanilla cross site scripting (XSS) attacks are possible.

An attacker may be able to cause execution of malicious scripting code in the browser of a user who clicks on a link or visits a malicious webpage. The malicious code would run in the security context of the vulnerable website.

This type of attack can result in non-persistent defacement of the target site, or the redirection of confidential information (i.e.: passwords or session IDs) to unauthorized third parties.

Solution


All JUNOS software releases built on or after 2010-05-28 have fixed this specific issue. Releases containing the fix specifically include: 8.5S8, 9.1S9, 9.3S10, 9.6S5, 10.0R3, 10.1R2, 10.2R1 and all subsequent releases (i.e. all releases built after 10.2R1).

This issue is being tracked as PR 475403. While this PR is not viewable by customers, it can be used as a reference when discussing the issue with JTAC.

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 Service Releases:

Security vulnerabilities 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 notices will indicate which Maintenance and/or 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


The most viable workaround for this issue is to either disable J-Web or permit access only from secure, trusted networks.

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."

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