CVE intelligence and bounded remediation
CVE-2020-27720 — F5 Big-Ip Carrier-Grade Nat security vulnerability
On BIG-IP LTM/CGNAT version 16.0.0-16.0.0.1, 15.1.0-15.1.0.5, 14.1.0-14.1.3, and 13.1.0-13.1.3.5, when processing NAT66 traffic with Port Block Allocation (PBA) mode and SP-DAG enabled, and dag-ipv6-prefix-len configured with a value less than the default of 128, an undisclosed traffic pattern may cause the Traffic Management Microkernel (TMM) to restart.
- Severity
- High
- CVSS
- 7.5 (3.1)
- Published
- 2020-12-24
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
Affected products
- f5 / big-ip_carrier-grade_nat
- f5 / big-ip_local_traffic_manager
Showing 2 representative product identities from 8 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.
Matched remediation archetype
General vulnerability remediation
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
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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