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Fencer Intel
high 7.8

CVE-2017-7814 json

File downloads encoded with "blob:" and "data:" URL elements bypassed normal file download checks though the Phishing and Malware Protectio…

published 2018-06-11 8 y ago modified 2026-06-17 4 mo ago also EUVD-2017-16789

cvss
7.8
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

File downloads encoded with "blob:" and "data:" URL elements bypassed normal file download checks though the Phishing and Malware Protection feature and its block lists of suspicious sites and files. This would allow malicious sites to lure users into downloading executables that would otherwise be detected as suspicious. This vulnerability affects Firefox < 56, Firefox ESR < 52.4, and Thunderbird < 52.4.

Patch / fix

  • Mozilla Firefox 56
  • Mozilla Firefox ESR 52.4
  • Mozilla Thunderbird 52.4
  • firefox-esr Debian 14, Debian 13, Debian 12 52.4.0esr-2
  • thunderbird Debian 14, Debian 13, Debian 12 1:52.4.0-1

debian advisories DEBIAN-CVE-2017-7814

  • firefox Ubuntu 14.04 LTS 56.0+build6-0ubuntu0.14.04.1
  • firefox Ubuntu 16.04 LTS 56.0+build6-0ubuntu0.16.04.1
  • firefox Ubuntu 18.04 LTS 56.0+build6-0ubuntu1
  • thunderbird Ubuntu 14.04 LTS 1:52.4.0+build1-0ubuntu0.14.04.2
  • thunderbird Ubuntu 16.04 LTS 1:52.4.0+build1-0ubuntu0.16.04.2
  • thunderbird Ubuntu 18.04 LTS 1:52.4.0+build1-0ubuntu2

ubuntu advisories UBUNTU-CVE-2017-7814

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

  • thunderbird RHEL 6 52.4.0-2.el6_9
  • thunderbird RHEL 7 52.4.0-2.el7_4
  • firefox RHEL 6 52.4.0-1.el6_9
  • firefox RHEL 7 52.4.0-1.el7_4

red hat advisories RHSA-2017:2885RHSA-2017:2831

  • mozilla-nss SLES 11 SP4, SLES 11 SP3-TERADATA, SLE Software Development Kit 11 SP4 +3 more 3.29.5-47.6.1
  • MozillaFirefox SLES 11 SP4, SLES 11 SP3-TERADATA, SLE Software Development Kit 11 SP4 +3 more 52.4.0esr-72.13.2
  • mozilla-nss SLES for SAP 12 SP3, SLES for SAP 12 SP2, SLES for SAP 12 SP1 +10 more 3.29.5-58.3.1
  • MozillaFirefox SLES for SAP 12 SP3, SLES for SAP 12 SP2, SLES for SAP 12 SP1 +10 more 52.4.0esr-109.6.2

suse advisories SUSE-SU-2017:2872-1SUSE-SU-2017:2872-2SUSE-SU-2017:2688-1

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaFirefox openSUSE Tumbleweed 92.0-1.2
  • MozillaThunderbird openSUSE Tumbleweed 91.1.1-1.1
  • MozillaThunderbird Package Hub 12 52.4.0-45.1

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:10600-1openSUSE-SU-2024:10601-1openSUSE-SU-2017:2707-1openSUSE-SU-2017:2710-1

  • thunderbird Arch Linux 52.4.0-1

arch linux advisories AVG-441

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2017-7814 updated cvss 7.8

Mozilla: Blob and data URLs bypass phishing and malware protection warnings (MFSA 2017-22)

  • Red Hat Enterprise Linux Client (v. 7) firefox 52.4.0-1.el7_4, thunderbird 52.4.0-2.el7_4 Red Hat Enterprise Linux Client Optional (v. 7) firefox 52.4.0-1.el7_4 Red Hat Enterprise Linux Desktop (v. 6) firefox 52.4.0-1.el6_9, thunderbird 52.4.0-2.el6_9 Red Hat Enterprise Linux Desktop Optional (v. 6) firefox 52.4.0-1.el6_9 Red Hat Enterprise Linux HPC Node Optional (v. 6) firefox 52.4.0-1.el6_9 Red Hat Enterprise Linux Server (v. 6) firefox 52.4.0-1.el6_9
    +7 more products
    Red Hat Enterprise Linux Server (v. 7) firefox 52.4.0-1.el7_4 Red Hat Enterprise Linux Server Optional (v. 6) firefox 52.4.0-1.el6_9, thunderbird 52.4.0-2.el6_9 Red Hat Enterprise Linux Server Optional (v. 7) firefox 52.4.0-1.el7_4, thunderbird 52.4.0-2.el7_4 Red Hat Enterprise Linux Workstation (v. 6) firefox 52.4.0-1.el6_9, thunderbird 52.4.0-2.el6_9 Red Hat Enterprise Linux Workstation (v. 7) firefox 52.4.0-1.el7_4, thunderbird 52.4.0-2.el7_4 Red Hat Enterprise Linux Workstation Optional (v. 6) firefox 52.4.0-1.el6_9 Red Hat Enterprise Linux Workstation Optional (v. 7) firefox 52.4.0-1.el7_4
    fixed: vendor fix RHSA-2017:2831

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.19% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.0 7.8 CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

  • Mozilla Firefox
  • Mozilla Firefox ESR
  • Mozilla Thunderbird

Classification

Weakness
  • CWE-20 Improper Input Validation

References

Sources

Fencer Intel 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.