CVE intelligence and bounded remediation

CVE-2018-18506 — Mozilla Firefox security vulnerability

Medium CVSS 5.9

When proxy auto-detection is enabled, if a web server serves a Proxy Auto-Configuration (PAC) file or if a PAC file is loaded locally, this PAC file can specify that requests to the localhost are to be sent through the proxy to another server. This behavior is disallowed by default when a proxy is manually configured, but when enabled could allow for attacks on services and tools that bind to the localhost for networked behavior if they are accessed through browsing. This vulnerability affects Firefox < 65.

Severity
Medium
CVSS
5.9 (3.1)
Published
2019-02-05
CISA KEV
Not currently listed
Ecosystem
browser

Affected products

  • mozilla / firefox
  • canonical / ubuntu_linux / 14.04
  • canonical / ubuntu_linux / 16.04
  • canonical / ubuntu_linux / 18.04
  • canonical / ubuntu_linux / 18.10
  • debian / debian_linux / 8.0

Showing 6 representative product identities from 29 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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