CVE-2018-12384 — When handling a SSLv2-compatible ClientHello request, the server doesn't generat

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 T

01What is this vulnerability?

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.

02Affected products

Vendor	Product	Versions
NSS	Network Security Services (NSS)	All versions prior to NSS 3.39

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2019-04-29T14:22:53.000Z
• Last modified: 2024-08-05T08:31:00.061Z

09References

• bugzilla.mozilla.org — https://bugzilla.mozilla.org/show_bug.cgi?id=CVE-2018-12384
• www.oracle.com — https://www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html