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Fencer Vulns
medium 5.3

CVE-2019-17021 json

During the initialization of a new content process, a race condition occurs that can allow a content process to disclose heap addresses fro…

published 2020-01-08 6 y ago modified 2026-06-17 4 mo ago also EUVD-2019-7495

cvss
5.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.9%
EPSS 1.9% chance of exploitation in 30 days, percentile 79%
public exploits
0
none known

Summary

During the initialization of a new content process, a race condition occurs that can allow a content process to disclose heap addresses from the parent process. *Note: this issue only occurs on Windows. Other operating systems are unaffected.*. This vulnerability affects Firefox ESR < 68.4 and Firefox < 72.

Patch / fix

  • mozilla firefox 72.0
  • mozilla firefox_esr 68.4
  • MozillaThunderbird SLE Workstation Extension 15 SP1, SLE Workstation Extension 15 68.4.1-3.66.1
  • MozillaFirefox SLE Module for Desktop Applications 15 SP1, SLE Module for Desktop Applications 15 68.4.1-3.66.1
  • MozillaFirefox SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +17 more 68.4.1-109.101.1
  • MozillaFirefox SLES 11 SP4-LTSS 68.4.1-78.57.1

suse advisories SUSE-SU-2020:0142-1SUSE-SU-2020:0078-1SUSE-SU-2020:14268-1SUSE-SU-2020:0068-1

  • MozillaThunderbird openSUSE Tumbleweed 91.1.1-1.1
  • MozillaThunderbird openSUSE Leap 15.1 68.4.1-lp151.2.22.2
  • MozillaFirefox openSUSE Leap 15.1 68.4.1-lp151.2.24.1

opensuse advisories openSUSE-SU-2024:10601-1openSUSE-SU-2020:0094-1openSUSE-SU-2020:0060-1

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-2019-17021 updated cvss 6.1

Mozilla: Heap address disclosure in parent process during content process initialization on Windows

  • Red Hat Enterprise Linux 5 firefox, thunderbird Red Hat Enterprise Linux 6 firefox, thunderbird Red Hat Enterprise Linux 7 firefox, thunderbird Red Hat Enterprise Linux 8 firefox, thunderbird
    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

1.87% chance of exploitation in the next 30 days, higher than 79% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • bugzilla.mozilla.org https://bugzilla.mozilla.org/show_bug.cgi?id=1599008 referenced PoC, tagged "exploit" by a source, unverified
  • packetstormsecurity.com http://packetstormsecurity.com/files/155912/Slackware-Security-Advisory-mozilla-thunderbird-Updates.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N
NVD 2.0 2.6 AV:N/AC:H/Au:N/C:P/I:N/A:N

Affected products

  • Mozilla Firefox ESR
  • Mozilla Firefox

Classification

Weakness
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization

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.