CVE intelligence and bounded remediation

CVE-2020-1679 — Juniper Junos security vulnerability

High CVSS 7.5

On Juniper Networks PTX and QFX Series devices with packet sampling configured using tunnel-observation mpls-over-udp, sampling of a malformed packet can cause the Kernel Routing Table (KRT) queue to become stuck. KRT is the module within the Routing Process Daemon (RPD) that synchronized the routing tables with the forwarding tables in the kernel. This table is then synchronized to the Packet Forwarding Engine (PFE) via the KRT queue. Thus, when KRT queue become stuck, it can lead to unexpected packet forwarding issues. An administrator can monitor the following command to check if there is the KRT queue is stuck: user@device > show krt state ... Number of async queue entries: 65007 <--- this value keep on increasing. When this issue occurs, the following message might appear in the /var/log/messages: DATE DEVICE kernel: %KERN-3: rt_pfe_veto: Too many delayed route/nexthop unrefs. Op 2 err 55, rtsm_id 5:-1, msg type 2 DATE DEVICE kernel: %KERN-3: rt_pfe_veto: Memory usage of M_RTNEXTHOP type = (0) Max size possible for M_RTNEXTHOP type = (7297134592) Current delayed unref = (60000), Current unique delayed unref = (18420), Max delayed unref on this platform = (40000) Current delay…

Severity
High
CVSS
7.5 (3.1)
Published
2020-10-16
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-20

Affected products

  • juniper / junos / 17.2x75
  • juniper / junos / 18.1

Showing 2 representative product identities from 103 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

General vulnerability remediation

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Check exposure

  • Confirm the affected component, deployment paths, reachable interfaces, and enabled features from inventories and configuration, without probing production destructively.
  • Compare the advisory's affected conditions with the repository lockfiles, build manifests, artifacts, and runtime inventory.
  • Identify data sensitivity, trust boundaries, and privilege level for every confirmed affected deployment.

Remediate safely

  • Apply a vendor-supported fix or remove the affected component or feature; record the selected change and its source in the repository.
  • Update direct and transitive dependency locks, generated artifacts, deployment manifests, and asset inventories together.
  • Add a regression test for the documented unsafe condition using inert inputs and preserve rollback instructions.

Authoritative sources

Complete CVE record and remediation plan

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