CVE-2019-12383

Tor Browser before 8.0.1 has an information exposure vulnerability. It allows remote attackers to detect the browser's UI locale by measuring a button width, even if the user has a "Don't send my language" setting.

Published: 2019-05-28 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2019-12383 is rated Moderate Risk (42.6/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.74%). Mandatory action: Review affected assets and schedule remediation.

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-2019-12383

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 2025-11-21 0.60% 0.74% +0.13%
2 2025-11-18 0.74% 0.60% -0.13%
3 2025-03-30 0.74%

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-12383

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
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:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 1.4 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
8.6 2.9 [email protected]

Weakness enumeration for CVE-2019-12383

OS Trackers for CVE-2019-12383

vendor priority summary link
debian unimportant CVE-2019-12383 unimportant priority: Debian including 2 source packages (firefox, firefox-esr), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 6. https://security-tracker.debian.org/tracker/CVE-2019-12383
ubuntu medium CVE-2019-12383 medium priority: Ubuntu including 6 source packages (firefox, firefox-esr, mozjs38, mozjs52, mozjs60, thunderbird), 36 status rows across 6 suites (bionic, cosmic, disco, trusty, upstream, xenial): not-affected 20, DNE 16. https://ubuntu.com/security/CVE-2019-12383

Affected software / configurations for CVE-2019-12383

Vendor Product Version Raw CPE
torproject tor_browser < 8.0.1 cpe:2.3:a:torproject:tor_browser:*:*:*:*:*:*:*:*

References for CVE-2019-12383

cvelogic Threat Intelligence