stb stb_truetype.h through 1.22 has a heap-based buffer over-read in ttUSHORT.
CVE-2020-6621
HIGHNVD 8.88.8—
EchelonGraph scoreMEDIUM confidence
This high-severity CVE scores 8.8 under NVD CVSS v3. EPSS exploit probability: 1.1% (65th percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, nvd
8.8EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1.1%CVSS: 8.8Exploit: None knownExposed services: —
No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.
Internet exposure
The internet-exposure footprint is temporarily unavailable — the KEV-Exposure radar's record for this CVE could not be loaded just now. That is not a finding of zero exposed services; please retry shortly.
- CVSS v3
- 8.8
- EG Score
- 8.8HIGHmedium confidence
- EG Risk
- 45EG Risk 45/100CISA SSVC
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity88% × 45%Exploitation1% × 40%Automatability30% × 15%CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix. - EPSS PROB
- 1.1%
- EPSS %ILE
- 65th
- KEV
- Not listed
CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).
No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table
Published
January 8, 2020
Last Modified
November 21, 2024
Advisory Details (1)
8.8
HIGH
2020-01-08 23:15:10.677+00
Affected: [{"url": "https://github.com/nothings/stb/issues/867", "tags": ["Exploit", "Third Party Advisory"], "source": "[email protected]"}, {"url": "https://github.com/nothings/stb/issues/867", "tags": ["Exploit", "Third Party Advisory"], "source": "af854a3a-2127-422b-91ae-364da2661108"}]
stb stb_truetype.h through 1.22 has a heap-based buffer over-read in ttUSHORT.Vendor Advisories for CVE-2020-6621
Vendor advisories for this CVE are temporarily unavailable — the list could not be loaded just now. That is not a sign that none exist; please retry shortly.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2020-6621?
CVE-2020-6621 is a high vulnerability published on January 8, 2020. stb stb_truetype.h through 1.22 has a heap-based buffer over-read in ttUSHORT.
When was CVE-2020-6621 disclosed?
CVE-2020-6621 was first published on January 8, 2020, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2020-6621 actively exploited?
CVE-2020-6621 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.1% probability of exploitation in the next 30 days (65th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2020-6621?
CVE-2020-6621 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2020-6621?
No fix for CVE-2020-6621 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2020-6621
Is Your Infrastructure Affected by CVE-2020-6621?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.