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CVE Record

CVE-2018-12434: LibreSSL before 2.6.5 and 2.7.x before 2.7.4 allows a memory-cache side-channel attack on DSA and ECDSA sig...

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.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This flaw can let a nearby attacker infer private signing keys from how vulnerable LibreSSL uses CPU cache during DSA or ECDSA signatures. It is not described as remotely exploitable by itself; the source says the attacker needs local access or a co-resident virtual machine on the same physical host.

Executive priority

Treat this as targeted cryptographic key risk, not a mass remote compromise. Prioritize assets that use LibreSSL for signing and run on shared or locally accessible systems. Urgency increases sharply for systems protecting customer trust, authentication, certificates, or regulated data.

Technical view

CVE-2018-12434 affects LibreSSL before 2.6.5 and 2.7.x before 2.7.4. It is a memory-cache side-channel issue in DSA and ECDSA signature operations, known as ROHNP. Successful exploitation can expose a signing key under local or same-host VM observation conditions.

Likely exposure

Exposure is most relevant where vulnerable LibreSSL versions perform DSA or ECDSA signing on shared infrastructure, multi-tenant virtualization, developer systems, or servers reachable by local users. The source bundle does not identify specific downstream products or package builds.

Exploitation context

No source in the bundle states active exploitation, and the CVE is not marked KEV. The attack requires proximity to the signing operation through local machine access or another VM on the same physical host, which limits broad internet exposure but matters for sensitive keys.

Researcher notes

The provided CVE data names LibreSSL version boundaries and attack preconditions but does not include CVSS, CWE, downstream product mapping, or confirmed exploitation. Analysis should focus on version validation, signing-key exposure, and tenant/local access assumptions.

Mitigation direction

  • Upgrade LibreSSL to 2.6.5, 2.7.4, or later as applicable.
  • Inventory systems and containers that bundle or link vulnerable LibreSSL versions.
  • Prioritize hosts performing DSA or ECDSA signing with high-value private keys.
  • Review vendor or OS package guidance for backported fixes.
  • Reduce co-tenancy risk for systems handling sensitive signing keys.

Validation and detection

  • Check deployed LibreSSL versions against the vulnerable ranges.
  • Identify workloads performing DSA or ECDSA signing through LibreSSL.
  • Confirm OS packages include the relevant LibreSSL security fix or backport.
  • Review shared-host and VM placement for sensitive signing services.
  • Verify upgrade completion through package inventory or runtime version checks.
Prepared
Confidence
high
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2018-12434 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
4Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.