Security readout for executives and security teams
Plain-English summary
This is an old Firefox cross-site scripting issue. A malicious site or response could cause affected Firefox versions to run attacker-controlled web script or HTML under certain HTTP error and content-sniffing conditions.
Executive priority
Treat as a legacy-browser hygiene issue unless affected versions are found. If present, prioritize removal because browser XSS can expose user sessions and business data through malicious web content.
Technical view
The CVE describes XSS in Firefox before 3.6.24 and Firefox 4.x through 7. The reported vectors involve HTTP 0.9 errors, non-default ports, and content-sniffing. No CVSS, CWE, detailed affected CPEs, or exploit status are provided in the bundle.
Likely exposure
Exposure is likely limited to environments still running the named legacy Firefox versions. Modern or centrally managed browser fleets are unlikely to be exposed, but inventories should confirm this rather than assume.
Exploitation context
The source bundle does not show CISA KEV listing or other evidence of active exploitation. The described attack requires a remote attacker to influence browser content handling through the stated HTTP and sniffing conditions.
Researcher notes
Evidence is sparse in the provided bundle: no CVSS vector, CWE, CPE list, patch advisory text, or exploit confirmation. Analysis is based on the CVE description and Mozilla Bugzilla reference only.
Mitigation direction
- Inventory Firefox versions across managed and unmanaged endpoints.
- Upgrade or remove Firefox versions before 3.6.24 and 4.x through 7.
- Check Mozilla guidance for any version-specific remediation details.
- Restrict internet access from affected legacy browsers until remediated.
Validation and detection
- Confirm endpoint inventory contains no affected Firefox versions.
- Review browser management policies for minimum allowed Firefox versions.
- Check proxy or EDR telemetry for legacy Firefox user agents.
- Document any business exception with compensating controls and owner.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2011-3656 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://bugzilla.mozilla.org/show_bug.cgi?id=667907CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.