CVE intelligence and bounded remediation
CVE-2018-18495 — WebExtension content scripts can be loaded into about: pages in some circumstances, in violation of the permissions granted to extensions
Medium
CVSS 6.5
WebExtension content scripts can be loaded into about: pages in some circumstances, in violation of the permissions granted to extensions. This could allow an extension to interfere with the loading and usage of these pages and use capabilities that were intended to be restricted from extensions. This vulnerability affects Firefox < 64.
- Severity
- Medium
- CVSS
- 6.5 (3.0)
- Published
- 2019-02-28
- CISA KEV
- Not currently listed
- Ecosystem
- browser
- Weaknesses
- CWE-732
Affected products
- mozilla / firefox
- canonical / ubuntu_linux / 14.04
- canonical / ubuntu_linux / 16.04
- canonical / ubuntu_linux / 18.04
- canonical / ubuntu_linux / 18.10
Matched remediation archetype
Privilege escalation and unsafe privilege management
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Map service accounts, operating-system identities, roles, capabilities, impersonation, set-user transitions, and administrative helper paths.
- Determine whether untrusted users or lower-privilege processes can reach the affected transition or modify inputs it trusts.
- Review file, socket, registry, device, job, container, and cloud-role permissions used before and after privilege changes.
Remediate safely
- Apply the supported fix and redesign privileged operations as a minimal, authenticated, allowlisted interface.
- Drop privileges before processing untrusted input, verify the drop succeeds, and remove unnecessary roles, capabilities, and write permissions.
- Validate ownership and permissions at time of use and add explicit lower-to-higher privilege boundary tests.
Authoritative sources
Complete CVE record and remediation plan
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