CVE-2018-12384

When handling a SSLv2-compatible ClientHello request, the server doesn't generate a new random value but sends an all-zero value instead. This results in full malleability of the ClientHello for SSLv2 used for TLS 1.2 in all versions prior to NSS 3.39. This does not impact TLS 1.3.

Published: 2019-04-29 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-12384 is rated Moderate Risk (49.2/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.49%). 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-2018-12384

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 0.62% 1.49% +0.87%
2 2026-05-14 0.68% 0.62% -0.06%
3 2026-05-01 — 0.68% —

Full EPSS history (22 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-12384

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.0 MEDIUM
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 3.6 [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-2018-12384

OS Trackers for CVE-2018-12384

vendor priority summary link
alpine medium CVE-2018-12384: 1 source package rows (nss); 11 state rows across 11 repos (3.10-main, 3.11-main, 3.12-main, 3.17-community, 3.18-community, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-community, edge-main); fixed 11, open 0. https://security.alpinelinux.org/vuln/CVE-2018-12384
debian low CVE-2018-12384 low priority: Debian including 1 source packages (nss), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2018-12384
redhat medium — https://access.redhat.com/security/cve/CVE-2018-12384
suse medium CVE-2018-12384 severity moderate: SUSE including 513 source package names (1.0.0.1862.1.5.2:libfreebl3-3.40.1-3.7.2, 1.0.0.1862.1.5.2:libsoftokn3-3.40.1-3.7.2, …), 1425 product×package rows across 338 product lines (Container bci/bci-sle15-kernel-module-devel, Container bci/kiwi, … (338 product lines)): Fixed 1113, Known Affected 157, Known Not Affected 155. https://www.suse.com/security/cve/CVE-2018-12384/
ubuntu low CVE-2018-12384 low priority: Ubuntu including 1 source packages (nss), 5 status rows across 5 suites (bionic, cosmic, trusty, upstream, xenial): released 5. https://ubuntu.com/security/CVE-2018-12384

Affected software / configurations for CVE-2018-12384

Vendor Product Version Raw CPE
mozilla network_security_services < 3.39 cpe:2.3:a:mozilla:network_security_services:*:*:*:*:*:*:*:*

References for CVE-2018-12384

cvelogic Threat Intelligence