CVE intelligence and bounded remediation
CVE-2021-23975 — The developer page about:memory has a Measure function for exploring what object types the browser has allocated and their sizes
Medium
CVSS 6.5
The developer page about:memory has a Measure function for exploring what object types the browser has allocated and their sizes. When this function was invoked we incorrectly called the sizeof function, instead of using the API method that checks for invalid pointers. This vulnerability affects Firefox < 86.
- Severity
- Medium
- CVSS
- 6.5 (3.1)
- Published
- 2021-02-26
- CISA KEV
- Not currently listed
- Ecosystem
- browser
- Weaknesses
- CWE-862
Affected products
- mozilla / firefox
Matched remediation archetype
Authorization bypass, IDOR, and cross-tenant access
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Map object and action authorization checks across API, UI, batch, import/export, and background-job paths.
- Identify tenant, ownership, role, and policy boundaries for affected resources and administrative operations.
- Use synthetic fixtures to compare intended access matrices without accessing another user's real data.
Remediate safely
- Enforce server-side authorization at each resource access and state transition using the authenticated principal and trusted tenant context.
- Scope data queries by tenant and ownership; treat client-supplied identifiers, roles, and policy claims as untrusted.
- Add deny-by-default policy tests for horizontal and vertical access across every affected transport.
Authoritative sources
Complete CVE record and remediation plan
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