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TI-2020-12333 Aliases CVE-2020-15658GHSA-5c48-vfr3-8jxq

Improper check for unusual conditions in Mozilla Firefox ESR

Priority LOW 32CWE-754Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · High · None
Fix status
Partial Red Hat: 9 fixed, 4 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.

Summary

The code for downloading files did not properly take care of special characters, which led to an attacker being able to cut off the file ending at an earlier position, leading to a different file type being downloaded than shown in the dialog. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.

Why it matters now

EPSS 0.01388 72nd percentileScored 2026-11-07
Fix Partial Firefox ESR (Mozilla): 78.1Firefox (Mozilla): 79+1 more productRed Hat: 4 advisoriesRed Hat: 9 fixed, 4 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
MozillaFirefox ESRbefore 78.178.1Patch availableCNA
MozillaFirefoxbefore 7979Patch availableCNA
MozillaThunderbirdbefore 78.178.1Patch availableCNA
  • Firefox ESR VendorMozilla Affected before 78.1 Fixed in 78.1 Patch available CNA
  • Firefox VendorMozilla Affected before 79 Fixed in 79 Patch available CNA
  • Thunderbird VendorMozilla Affected before 78.1 Fixed in 78.1 Patch available CNA

CPE configurations NVD · 6

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*before 79.0VulnerableMozilla
cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*before 78.1VulnerableMozilla
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*before 78.1VulnerableMozilla
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*16.04VulnerableCanonical
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*18.04VulnerableCanonical
cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*20.04VulnerableCanonical
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 79.0 Vulnerable ·Mozilla
  • cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:* Versions before 78.1 Vulnerable ·Mozilla
  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions before 78.1 Vulnerable ·Mozilla
  • cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:* Versions 16.04 Vulnerable ·Canonical
  • cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* Versions 18.04 Vulnerable ·Canonical
  • cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:* Versions 20.04 Vulnerable ·Canonical

Remediation

  • Fix · CNA Firefox ESR (Mozilla) Fixed in 78.1
  • Fix · CNA Firefox (Mozilla) Fixed in 79
  • Fix · CNA Thunderbird (Mozilla) Fixed in 78.1

Red Hat 4 advisories

  • RHSA-2020:4080 Released 2020-09-30 · Red Hat rating Important
    firefox security and bug fix update
    • Red Hat Enterprise Linux Client (v. 7) firefox-78.3.0-1.el7_9
    • Red Hat Enterprise Linux Client Optional (v. 7) firefox-78.3.0-1.el7_9
    • Red Hat Enterprise Linux Server (v. 7) firefox-78.3.0-1.el7_9
    • Red Hat Enterprise Linux Server Optional (v. 7) firefox-78.3.0-1.el7_9
    • Red Hat Enterprise Linux Workstation (v. 7) firefox-78.3.0-1.el7_9
    • Red Hat Enterprise Linux Workstation Optional (v. 7) firefox-78.3.0-1.el7_9
  • RHSA-2020:3559 Released 2020-08-26 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream EUS (v. 8.1) firefox-78.2.0-3.el8_1
  • RHSA-2020:3557 Released 2020-08-26 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 8) firefox-78.2.0-2.el8_2
Show 1 more Red Hat advisories
  • RHSA-2020:3555 Released 2020-08-26 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream E4S (v. 8.0) firefox-78.2.0-3.el8_0

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    Mozilla Firefox 79

    8 records Highest priority Priority MEDIUM 2 MEDIUM, 6 LOW

    Other records, highest priority first

    • TI-2020-12334 Out-of-bounds write in Mozilla FirefoxPriority MEDIUM 43
    • TI-2020-12331 Type confusion in Mozilla Firefox ESRPriority MEDIUM 41
    • TI-2020-12332 Uncontrolled search path in Mozilla Firefox ESRPriority LOW 34
    Show all 8 records →
  • Release ·

    Mozilla Firefox ESR, Thunderbird 78.1

    6 records Highest priority Priority MEDIUM 1 MEDIUM, 5 LOW

    Other records, highest priority first

    • TI-2020-12331 Type confusion in Mozilla Firefox ESRPriority MEDIUM 41
    • TI-2020-12332 Uncontrolled search path in Mozilla Firefox ESRPriority LOW 34
    • TI-2020-12330 A redirected HTTP request which is observed or modified through a web extension could…Priority LOW 32
    Show all 6 records →

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 5AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Will not fix
Red Hat Enterprise Linux 8AffectedNo fix planned: Will not fix
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2020:3557
Red Hat Enterprise Linux AppStream E4S (v. 8.0)Fixed RHSA-2020:3555
Red Hat Enterprise Linux AppStream EUS (v. 8.1)Fixed RHSA-2020:3559
Red Hat Enterprise Linux Client (v. 7)Fixed RHSA-2020:4080
Red Hat Enterprise Linux Client Optional (v. 7)Fixed RHSA-2020:4080
Red Hat Enterprise Linux Server (v. 7)Fixed RHSA-2020:4080
Red Hat Enterprise Linux Server Optional (v. 7)Fixed RHSA-2020:4080
Red Hat Enterprise Linux Workstation (v. 7)Fixed RHSA-2020:4080
Red Hat Enterprise Linux Workstation Optional (v. 7)Fixed RHSA-2020:4080
Not affected: 1 product
  • Red Hat Enterprise Linux 5

Timeline

  1. 2026-10-02 Threatist record created from CVE-2020-15658
  2. 2026-10-03 Alias added: GHSA-5c48-vfr3-8jxq

References

Advisory 6

  • TI-2024-08981 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.8
  • TI-2022-09832 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.6
  • TI-2019-08769 Improper input validation in Mozilla Firefox ESR KEVCVSS 3.1CRITICAL 10.0
  • TI-2010-03577 Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before… KEVCVSS 3.1CRITICAL 9.8
  • TI-2023-04799 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
  • TI-2023-04477 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
See all 3444 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences