CVE-2018-16983

NoScript Classic before 5.1.8.7, as used in Tor Browser 7.x and other products, allows attackers to bypass script blocking via the text/html;/json Content-Type value.

Published: 2018-09-13 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2018-16983 is rated High Risk (72.1/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 3.12%). Core evidence: EPSS rose +2.72% over the last day, indicating growing attacker interest. Mandatory action: High exploitation likelihood—assess exposure and prioritize 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-2018-16983

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 0.40% 3.12% +2.72%
2 2026-03-04 0.49% 0.40% -0.09%
3 2026-03-01 0.49%

Full EPSS history (39 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-16983

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.0 CRITICAL
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 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: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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
10.0 6.4 [email protected]

Weakness enumeration for CVE-2018-16983

OS Trackers for CVE-2018-16983

vendor priority summary link
ubuntu negligible CVE-2018-16983 negligible priority: Ubuntu including 1 source packages (mozilla-noscript), 4 status rows across 4 suites (bionic, trusty, upstream, xenial): DNE 3, needs-triage 1. https://ubuntu.com/security/CVE-2018-16983

Affected software / configurations for CVE-2018-16983

Vendor Product Version Raw CPE
noscript noscript < 5.1.8.7 cpe:2.3:a:noscript:noscript:*:*:*:*:*:*:*:*
torproject tor_browser >= 7.0.0, <= 7.0.11 cpe:2.3:a:torproject:tor_browser:*:*:*:*:*:*:*:*

References for CVE-2018-16983

cvelogic Threat Intelligence