CVE-2020-15666
Low
No strong exploitation signal.
CVSS base
6.5
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
EPSS — probability of exploitation (30 days)
1.2%
67.6th percentile
CISA KEV
Not listed
Weakness / dates
CWE-209
Published 2020-10-01 · modified 2026-08-19
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | N | None |
| User Interaction | R | Required |
| Scope | U | Unchanged |
| Confidentiality | H | High |
| Integrity | N | None |
| Availability | N | None |
Timeline
- 2020-10-01 — Published (NVD)
- 2026-08-19 — Last modified (NVD)
Description
When trying to load a non-video in an audio/video context the exact status code (200, 302, 404, 500, 412, 403, etc.) was disclosed via the MediaError Message. This level of information leakage is inconsistent with the standardized onerror/onsuccess disclosure and can lead to inferring login status to services or device discovery on a local network among other attacks. This vulnerability affects Firefox < 80 and Firefox for Android < 80.
Affected
References
- exploit https://bugzilla.mozilla.org/show_bug.cgi?id=1450853
- https://www.mozilla.org/security/advisories/mfsa2020-36/
- https://www.mozilla.org/security/advisories/mfsa2020-39/
- exploit https://bugzilla.mozilla.org/show_bug.cgi?id=1450853
- https://www.mozilla.org/security/advisories/mfsa2020-36/
- https://www.mozilla.org/security/advisories/mfsa2020-39/