What is the CVSS score of CVE-2018-5731?

CVE-2018-5731 has a CVSS 3.0 base score of 7.0 (High). CVSS vector: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.4%.

Is there a public PoC exploit available for CVE-2018-5731?

Yes, a public proof-of-concept exploit is available for CVE-2018-5731. Prioritise patching immediately. EPSS: 0.4%.

Heimdal CVE-2018-5731

HIGH

Improper Input Validation (CWE-20)

2018-03-22 cve@mitre.org

Information Disclosure Microsoft Heimdal Heimdalsecurity

7.0

CVSS 3.0 · NVD

View

Vulnerability Assessment

Weakness	CWE CWE-20 OWASP Top 10:2025 A05:2025 - Injection ASVS 5.0 V2 - Validation and Business Logic Input validation, allowlisting
Impact	CVSS score of 7.0 (HIGH). Attack characteristics: local attack vector, high complexity, low privileges required, no user interaction not required. Public proof-of-concept exploit code is available.
Exploit ScenarioDerived	Successful exploitation could compromise the high-severity affected system.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

No patch listed yet 0.4% exploitation probability (EPSS)

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AnalysisAI

An issue was discovered in Heimdal PRO 2.2.190. Rated high severity (CVSS 7.0). Public exploit code available and no vendor patch available.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.

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Technical ContextAI · show details

This vulnerability is classified under CWE-20. An issue was discovered in Heimdal PRO 2.2.190. As part of the scanning feature, a process called md.hs writes an executable called CS1.tmp to C:\windows\TEMP. Afterwards the executable is run. It is possible for an attacker to create the file first, let md.hs overwrite it, and then rewrite the file in the window between md.hs closing the file and executing it. This can be exploited via opportunistic locks and a high priority thread. The vulnerability is triggered when a scan starts. NOTE: any affected Heimdal products are completely unrelated to the Heimdal vendor of a Kerberos 5 product on the h5l.org web site. Affected products include: Heimdalsecurity Heimdal.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 7.0 HIGH

AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Local

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

DescriptionNVD

An issue was discovered in Heimdal PRO 2.2.190. As part of the scanning feature, a process called md.hs writes an executable called CS1.tmp to C:\windows\TEMP. Afterwards the executable is run. It is possible for an attacker to create the file first, let md.hs overwrite it, and then rewrite the file in the window between md.hs closing the file and executing it. This can be exploited via opportunistic locks and a high priority thread. The vulnerability is triggered when a scan starts. NOTE: any affected Heimdal products are completely unrelated to the Heimdal vendor of a Kerberos 5 product on the h5l.org web site.

Threat Intelligence Overview

EPSS Score

0.4%

Top 66% exploitable

Exploit

POC

Public exploit code exists

Data Quality

2 sources

Confidence: Low

NVD

CVE.org

EPSS

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV No

Public POC Yes

EPSS 0.4%

Patch available No

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Scheduled

Exploitation· derived

Poc

System Exposure· derived

Small

Automatable· derived

Human Impact· derived

Medium

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +35

PoC: +20

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Information Disclosure MEDIUM

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.