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2012-07 Security Bulletin: Junos: J-Web vulnerable to hash table collision attacks (CVE-2011-3414)

  [JSA10522] Show Article Properties

Legacy Advisory Id:
Product Affected:
This issue can affect all Junos routers and gateways with J-Web enabled.

A function within the hash table implementation computes hash values for form parameters without restricting the ability to trigger hash collisions predictably. This can allow remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters.

This issue is also known by the title, "Collisions in HashTable May Cause DoS Vulnerability."

Juniper SIRT is not aware of any malicious exploitation of this vulnerability against Juniper products.

No other Juniper Networks products or platforms are affected by this issue.

Added max_input_time to restrict CPU time available for processing HTTP request inputs.

All Junos OS software releases built on or after 2012-05-30 have fixed this specific issue. Releases containing the fix specifically include: 10.0S25, 10.4R10, 11.2R7, 11.3R6, 11.4R3, 12.1R2 and all subsequent releases (i.e. all releases built after 12.1R2).

This issue is being tracked as PR 731578 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 from only trusted hosts.

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.
Related Links:
CVSS Score:
7.8 (AV:N/AC:L/Au:N/C:N/I:N/A:C)
Severity Level:
Severity Assessment:
Information for how Juniper Networks uses CVSS can be found at KB 16446 "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."