CVE intelligence and bounded remediation
CVE-2017-7821 — A vulnerability where WebExtensions can download and attempt to open a file of some non-executable file types
Critical
CVSS 9.8
A vulnerability where WebExtensions can download and attempt to open a file of some non-executable file types. This can be triggered without specific user interaction for the file download and open actions. This could be used to trigger known vulnerabilities in the programs that handle those document types. This vulnerability affects Firefox < 56.
- Severity
- Critical
- CVSS
- 9.8 (3.0)
- Published
- 2018-06-11
- CISA KEV
- Not currently listed
- Ecosystem
- browser
- Weaknesses
- CWE-732
Affected products
- mozilla / firefox
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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