Junos: Firewall filter fails to match on port

The issue only affects routers utilizing Trio-based PFE modules running Junos OS 13.3R3, 14.1R1, and 14.1R2 

When configuring a stateless firewall filter on a system with Trio-based PFE modules (e.g. MX Series), any source or destination port matching condition may fail to match intended packets, causing the filter to not execute the actions specified in the 'then' clause.​​​​ Depending on the intent and design of the interface filter, this match failure may have unexpected impact on the router or follow-on filter clauses. For example, if traffic with a specific destination port was designed to be accepted, a later "reject all" clause may inadvertently discard wanted traffic. Conversely, if certain destination ports are meant to be dropped, malicious traffic may be consumed by the RE or forwarded on to downstream routers.

This issue only affects routers running Junos OS 13.3R3, 14.1R1, and 14.1R2. Additionally, this issue only affects IPv4 traffic. IPv6 port matching filters are unaffected by this issue.


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

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

The following software releases have been updated to resolve this specific issue: Junos OS 13.3R3-S3​, 13.3R4, 14.1R3, 14.2R1, and all subsequent releases.

This issue is being tracked as PR 1003494 ​and is visible on the Customer Support website.

Note: While the vulnerability does not impact versions of Junos prior to 13.3R3, the actual code modified to resolve the issue existed in earlier releases. For this reason, the prsearch tool will report fixes in Junos OS 12.3R8 and 13.2R6, even though the vulnerability was never exposed in these releases.

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.