What is the CVSS score of CVE-2020-6623?

CVE-2020-6623 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. EPSS exploitation probability: 1.5%.

Is there a public PoC exploit available for CVE-2020-6623?

Yes, a public proof-of-concept exploit is available for CVE-2020-6623. Prioritise patching immediately. EPSS: 1.5%.

Stb Truetype H CVE-2020-6623

HIGH

Reachable Assertion (CWE-617)

2020-01-08 cve@mitre.org

Denial Of Service Stb Truetype H Nothings

8.8

CVSS 3.1 · NVD

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Vulnerability Assessment

Weakness	CWE CWE-617 ASVS 5.0 V16 - Security Logging and Error Handling Reachable assertion handling
Impact	CVSS score of 8.8 (HIGH). Attack characteristics: network attack vector, low complexity, no privileges required, user interaction required. Public proof-of-concept exploit code is available.
Exploit ScenarioDerived	This vulnerability can be exploited remotely over the network. 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 1.5% exploitation probability (EPSS)

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AnalysisAI

stb stb_truetype.h through 1.22 has an assertion failure in stbtt__cff_get_index. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. 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.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified under CWE-617. stb stb_truetype.h through 1.22 has an assertion failure in stbtt__cff_get_index. Affected products include: Nothings Stb Truetype.H. Version information: through 1.22.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 8.8 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

DescriptionNVD

stb stb_truetype.h through 1.22 has an assertion failure in stbtt__cff_get_index.

Threat Intelligence Overview

EPSS Score

1.5%

Top 30% exploitable

Exploit

POC

Public exploit code exists

Data Quality

3 sources

Confidence: Low

NVD

CVE.org

EPSS

GitHub

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 1.5%

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.