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Fencer Vulns
high 7.8

CVE-2019-11753 json

The Firefox installer allows Firefox to be installed to a custom user writable location, leaving it unprotected from manipulation by unpriv…

published 2019-09-27 7 y ago modified 2026-06-17 4 mo ago also EUVD-2019-3423

cvss
7.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 13%
public exploits
0
none known

Summary

The Firefox installer allows Firefox to be installed to a custom user writable location, leaving it unprotected from manipulation by unprivileged users or malware. If the Mozilla Maintenance Service is manipulated to update this unprotected location and the updated maintenance service in the unprotected location has been altered, the altered maintenance service can run with elevated privileges during the update process due to a lack of integrity checks. This allows for privilege escalation if the executable has been replaced locally. <br>*Note: This attack requires local system access and only affects Windows. Other operating systems are not affected.*. This vulnerability affects Firefox < 69, Firefox ESR < 60.9, and Firefox ESR < 68.1.

Patch / fix

  • Mozilla Firefox 69
  • Mozilla Firefox ESR 60.9, 68.1
  • MozillaFirefox SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +18 more 68.1.0-109.89.1
  • MozillaFirefox-branding-SLE SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +16 more 68-32.8.1
  • MozillaFirefox SLE Module for Desktop Applications 15 SP1, SLE Module for Desktop Applications 15 68.1.0-3.54.2
  • MozillaFirefox-branding-SLE SLE Module for Desktop Applications 15 SP1, SLE Module for Desktop Applications 15 68-4.8.5
  • MozillaFirefox SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +18 more 60.9.0-109.86.1
  • firefox-atk SLES 11 SP4-LTSS 2.26.1-2.8.4
  • mozilla-nss SLES 11 SP4-LTSS 3.45-38.9.3
  • firefox-gtk3 SLES 11 SP4-LTSS 3.10.9-2.15.3

suse advisories SUSE-SU-2019:14246-1SUSE-SU-2019:2620-1SUSE-SU-2019:2545-1SUSE-SU-2019:2436-1SUSE-SU-2019:14173-1

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaFirefox openSUSE Tumbleweed 92.0-1.2
  • MozillaFirefox openSUSE Leap 15.0 68.1.0-lp150.3.66.1
  • MozillaFirefox openSUSE Leap 15.1 68.1.0-lp151.2.14.1

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:10600-1openSUSE-SU-2019:2260-1openSUSE-SU-2019:2251-1

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-2019-11753 updated cvss 7.0

Mozilla: Privilege escalation with Mozilla Maintenance Service in custom Firefox installation location

  • Red Hat Enterprise Linux 5 firefox
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 6 firefox Red Hat Enterprise Linux 7 firefox Red Hat Enterprise Linux 8 firefox
    not affected: vulnerable code not present

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

0.23% chance of exploitation in the next 30 days, higher than 13% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 4.6 AV:L/AC:L/Au:N/C:P/I:P/A:P

Affected products

  • Mozilla Firefox
  • Mozilla Firefox ESR

Classification

Weakness
  • CWE-354 Improper Validation of Integrity Check Value

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.