HOMEVULNERABILITIESCVE-2020-12389
CRITICAL

CVE-2020-12389

CWE-20Published: May 26, 2020· Updated: Jun 17, 2026

10.0
CVSS v3.1

Official Description

The Firefox content processes did not sufficiently lockdown access control which could result in a sandbox escape. *Note: this issue only affects Firefox on Windows operating systems.*. This vulnerability affects Firefox ESR < 68.8 and Firefox < 76.

NVD Source

Technical Analysis

CVE-2020-12389 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 10.0.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeChanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected Vendors & Products

Microsoft1 product(s)
windows
Mozilla2 product(s)
firefoxfirefox esr
Source: NVD CPE · 3 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

All References (6)

Quick Facts

CVE IDCVE-2020-12389
CVSS Score10.0 / 10
SeverityCRITICAL
WeaknessCWE-20
CISA KEVNo
Affected2 vendor(s)
PublishedMay 26, 2020

Related CVEs (CWE-20)

Recommended Actions

  • Apply vendor patches immediately
  • Monitor CVE-2020-12389 in threat intel feeds
  • Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.