CVE-2018-12434 — LibreSSL before 2

LibreSSL before 2.6.5 and 2.7.x before 2.7.4 allows a memory-cache side-channel attack on DSA and ECDSA signatures, aka the Return Of the Hidden Number Problem or ROHNP. To discover a key, the attacker needs access to either the local machine or a different virtual machine on the

01What is this vulnerability?

LibreSSL before 2.6.5 and 2.7.x before 2.7.4 allows a memory-cache side-channel attack on DSA and ECDSA signatures, aka the Return Of the Hidden Number Problem or ROHNP. To discover a key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

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: 2018-06-15T02:00:00.000Z
• Last modified: 2024-09-16T22:52:15.412Z

09References

• ftp.openbsd.org — https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-2.7.4-relnotes.txt
• www.nccgroup.trust — https://www.nccgroup.trust/us/our-research/technical-advisory-return-of-the-hidd…
• ftp.openbsd.org — https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-2.6.5-relnotes.txt