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Fencer Vulns
medium 5.3

CVE-2018-5142 json

If Media Capture and Streams API permission is requested from documents with "data:" or "blob:" URLs, the permission notifications do not p…

published 2018-06-11 8 y ago modified 2026-06-17 4 mo ago also EUVD-2018-16928

cvss
5.3
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.2%
EPSS 1.2% chance of exploitation in 30 days, percentile 68%
public exploits
0
none known

Summary

If Media Capture and Streams API permission is requested from documents with "data:" or "blob:" URLs, the permission notifications do not properly display the originating domain. The notification states "Unknown protocol" as the requestee, leading to user confusion about which site is asking for this permission. This vulnerability affects Firefox < 59.

Patch / fix

  • Mozilla Firefox 59
  • firefox Ubuntu 14.04 LTS 59.0+build5-0ubuntu0.14.04.1
  • firefox Ubuntu 16.04 LTS 59.0+build5-0ubuntu0.16.04.1
  • firefox Ubuntu 18.04 LTS 59.0.1+build1-0ubuntu1

ubuntu advisories UBUNTU-CVE-2018-5142

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaFirefox openSUSE Tumbleweed 92.0-1.2

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:10600-1

Exploit prediction

1.19% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.0 5.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N

Affected products

  • Mozilla Firefox

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.