CVE-2018-12439
CWE-200Published: June 15, 2018· Updated: Jun 17, 2026
Official Description
MatrixSSL through 3.9.5 Open allows a memory-cache side-channel attack on ECDSA signatures, aka the Return Of the Hidden Number Problem or ROHNP. To discover an ECDSA key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.
Technical Analysis
CVE-2018-12439 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
A successful exploit results in complete confidentiality breach (data exposure), with a CVSS base score of 4.7.
From a weakness classification perspective (CWE-200): Information exposure vulnerabilities leak sensitive data to unauthorized actors.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (2)
Quick Facts
Related CVEs (CWE-200)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2018-12439 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts