VIR Vulnerability Intelligence Relay

CVE-2015-4520

medium
Published 2015-09-24 · Modified 2026-05-06
💬 Discuss on Community ✚ Propose mitigation
CVSS v3
—
CVSS v4 NEW
—
not yet in upstream
VIR risk
6.4

Description

Mozilla Firefox before 41.0 and Firefox ESR 38.x before 38.3 allow remote attackers to bypass CORS preflight protection mechanisms by leveraging (1) duplicate cache-key generation or (2) retrieval of a value from an incorrect HTTP Access-Control-* response header.

Predictions

Exploit likelihood
20%
Patch ETA
—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

Application impact
VendorProductVersionsFixed
mozilla mozillafirefox38.0
mozilla mozillafirefox38.0.1
mozilla mozillafirefox38.0.5
mozilla mozillafirefox38.1.0
mozilla mozillafirefox38.1.1
mozilla mozillafirefox38.2.0
mozilla mozillafirefox38.2.1
mozilla mozillafirefox{"endIncluding":"40.0.3"}

References

CWEs

CWE-254

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.