How severe is CVE-2018-12384?

CVE-2018-12384 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2018-12384 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-12384?

CVE-2018-12384 affects Mozilla Network Security Services. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-12384?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2018-12384 published?

CVE-2018-12384 was published on 2019-04-29 and last updated on 2026-06-17.

CVE-2018-12384

CVE-2018-12384 is a medium-severity vulnerability in Mozilla Network Security Services with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-335.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v2: 4.3
EPSS exploit prediction: 1% (71st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-335
Affected product: Mozilla Network Security Services
Published: 2019-04-29
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2018-12384?: CVE-2018-12384 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2018-12384 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-12384?: CVE-2018-12384 affects Mozilla Network Security Services. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-12384?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-12384 published?: CVE-2018-12384 was published on 2019-04-29 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mozilla:network_security_services:*:*:*:*:*:*:*:*

More vulnerabilities in Mozilla Network Security Services

CVE-2014-1544 — Critical (CVSS 10.0): Use-after-free vulnerability in the CERT_DestroyCertificate function in libnss3.so in Mozilla Network Security Services…
CVE-2019-17006 — Critical (CVSS 9.8): In Network Security Services (NSS) before 3.46, several cryptographic primitives had missing length checks. In cases…
CVE-2017-5461 — Critical (CVSS 9.8): Mozilla Network Security Services (NSS) before 3.21.4, 3.22.x through 3.28.x before 3.28.4, 3.29.x before 3.29.5, and…
CVE-2015-7182 — Critical (CVSS 9.8): Heap-based buffer overflow in the ASN.1 decoder in Mozilla Network Security Services (NSS) before 3.19.2.1 and 3.20.x…
CVE-2014-1490 — Critical (CVSS 9.3): Race condition in libssl in Mozilla Network Security Services (NSS) before 3.15.4, as used in Mozilla Firefox before…
CVE-2009-2404 — Critical (CVSS 9.3): Heap-based buffer overflow in a regular-expression parser in Mozilla Network Security Services (NSS) before 3.12.3, as…

All CVEs affecting Mozilla Network Security Services →

Other CWE-335 vulnerabilities

CVE-2024-36048 — Critical (CVSS 9.8): QAbstractOAuth in Qt Network Authorization in Qt before 5.15.17, 6.x before 6.2.13, 6.3.x through 6.5.x before 6.5.6,…
CVE-2023-4472 — Critical (CVSS 9.8): Objectplanet Opinio version 7.22 and prior uses a cryptographically weak pseudo-random number generator (PRNG) coupled…
CVE-2012-1577 — Critical (CVSS 9.8): lib/libc/stdlib/random.c in OpenBSD returns 0 when seeded with 0.
CVE-2019-11495 — Critical (CVSS 9.8): In Couchbase Server 5.1.1, the cookie used for intra-node communication was not generated securely. Couchbase Server…
CVE-2019-10908 — Critical (CVSS 9.8): In Airsonic 10.2.1, RecoverController.java generates passwords via org.apache.commons.lang.RandomStringUtils, which…
CVE-2017-11519 — Critical (CVSS 9.8): passwd_recovery.lua on the TP-Link Archer C9(UN)_V2_160517 allows an attacker to reset the admin password by leveraging…

Browse all CWE-335 vulnerabilities →