CVE-2020-12394

A logic flaw in our location bar implementation could have allowed a local attacker to spoof the current location by selecting a different origin and removing focus from the input element. This vulnerability affects Firefox < 76.

Published: 2020-05-26 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-12394 is rated Low Risk (20/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.27%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-12394

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.14% 0.27% +0.14%
2 2026-05-27 0.15% 0.14% -0.01%
3 2025-11-21 — 0.15% —

Full EPSS history (12 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-12394

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
3.3 3.1 LOW
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 1.8 1.4 [email protected]
2.1 2.0 LOW
AV:L/AC:L/Au:N/C:N/I:P/A:N Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 3.9 2.9 [email protected]

Weakness enumeration for CVE-2020-12394

OS Trackers for CVE-2020-12394

vendor priority summary link
alpine low CVE-2020-12394: 2 source package rows (firefox, librewolf); 22 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 10, open 12. https://security.alpinelinux.org/vuln/CVE-2020-12394
debian not yet assigned CVE-2020-12394 not yet assigned priority: Debian including 1 source packages (firefox), 1 status rows across 1 suites (sid): resolved 1. https://security-tracker.debian.org/tracker/CVE-2020-12394
gentoo normal CVE-2020-12394: 1 GLSA(s) (202005-04), 2 atom(s) (www-client/firefox, www-client/firefox-bin); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2020-12394
redhat low — https://access.redhat.com/security/cve/CVE-2020-12394
ubuntu medium CVE-2020-12394 medium priority: Ubuntu including 5 source packages (firefox, mozjs38, mozjs52, mozjs60, mozjs68), 70 status rows across 14 suites (bionic, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, trusty, upstream, xenial): DNE 45, released 13, ignored 12. https://ubuntu.com/security/CVE-2020-12394

Affected software / configurations for CVE-2020-12394

Vendor Product Version Raw CPE
mozilla firefox < 76.0 cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*

References for CVE-2020-12394

cvelogic Threat Intelligence