Skip to content

CVE-2020-15999 — Heap buffer overflow in Freetype in Google Chrome prior to 86.0.4240.111 allowed a remote…

Key facts

CVE-2020-15999 is a Critical (9.6) vulnerability: Heap buffer overflow in Freetype in Google Chrome prior to 86.0.4240.111 allowed a remote…. This entry ships a detection-only PoC and a Docker test lab. It is on the CISA Known Exploited Vulnerabilities (KEV) catalog (added 2021-11-03), confirming active exploitation in the wild.

Actively exploited — on the CISA KEV catalog

CVE-2020-15999 is listed on the CISA Known Exploited Vulnerabilities (KEV) catalog (added 2021-11-03), confirming exploitation in the wild. Federal remediation deadline: 2021-11-17. Prioritise patching and deploy the detection and prevention rules below.
CVE CVE-2020-15999
Severity Critical (9.6)
CISA KEV Actively exploited (added 2021-11-03)
Detection / prevention —
PoC poc.py
Source 2020/CVE-2020-15999/

Details

English | 한국어

Description

Heap buffer overflow in Freetype in Google Chrome prior to 86.0.4240.111 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.

Vulnerability Details

Property Value
CVE ID CVE-2020-15999
CVSS Score 9.6

Proof of Concept

Download

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2020/CVE-2020-15999/poc.py

Usage

# Run PoC against target
python3 poc.py --target <TARGET_URL>

# With authentication
python3 poc.py --target <TARGET_URL> --username <USER> --password <PASS>

⚠️ Warning: This PoC is for authorized security testing only. It uses detection-only techniques and does not exploit or damage target systems.

Test Lab

This repository includes a Docker-based test environment with both vulnerable and patched applications.

Quick Start

# Clone and navigate to CVE directory
cd CVE-2020-15999

# Start both applications
docker-compose up -d

# Run tests
./run-tests.sh    # Linux/Mac
./run-tests.ps1   # Windows PowerShell

Application Endpoints

Application URL Status
Vulnerable App http://localhost:8080 Shows vulnerability
Patched App http://localhost:8081 Demonstrates fix

Directory Structure

├── README.md           # English documentation
├── README_KO.md        # Korean documentation
├── poc.py              # PoC detection script
├── docker-compose.yml  # Container orchestration
├── run-tests.sh        # Linux/Mac test runner
├── run-tests.ps1       # Windows test runner
├── vulnerable-app/     # Vulnerable version
│   ├── app.py
│   ├── Dockerfile
│   └── requirements.txt
└── patched-app/        # Fixed version
    ├── app.py
    ├── Dockerfile
    └── requirements.txt

References

  • http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00016.html
  • http://seclists.org/fulldisclosure/2020/Nov/33
  • https://chromereleases.googleblog.com/2020/10/stable-channel-update-for-desktop_20.html
  • https://crbug.com/1139963
  • https://googleprojectzero.blogspot.com/p/rca-cve-2020-15999.html
  • https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/J3QVIGAAJ4D62YEJAJJWMCCBCOQ6TVL7/
  • https://security.gentoo.org/glsa/202011-12
  • https://security.gentoo.org/glsa/202012-04
  • https://security.gentoo.org/glsa/202401-19
  • https://www.debian.org/security/2021/dsa-4824
  • http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00016.html
  • http://seclists.org/fulldisclosure/2020/Nov/33
  • https://chromereleases.googleblog.com/2020/10/stable-channel-update-for-desktop_20.html
  • https://crbug.com/1139963
  • https://googleprojectzero.blogspot.com/p/rca-cve-2020-15999.html
  • https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/J3QVIGAAJ4D62YEJAJJWMCCBCOQ6TVL7/
  • https://security.gentoo.org/glsa/202011-12
  • https://security.gentoo.org/glsa/202012-04
  • https://security.gentoo.org/glsa/202401-19
  • https://security.netapp.com/advisory/ntap-20240812-0001/
  • https://www.debian.org/security/2021/dsa-4824
  • https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-15999

Generated by PoC Generator on 2026-07-08T11:38:58.224835289

Frequently asked questions

What is CVE-2020-15999?

CVE-2020-15999 is a Critical (9.6) vulnerability: Heap buffer overflow in Freetype in Google Chrome prior to 86.0.4240.111 allowed a remote…. This entry ships a detection-only PoC and a Docker test lab. It is on the CISA Known Exploited Vulnerabilities (KEV) catalog (added 2021-11-03), confirming active exploitation in the wild.

How do I detect CVE-2020-15999?

Run the detection-only PoC included with this entry against your Docker test lab to confirm whether a target is affected; pair it with your own IDS logging.

How do I block or mitigate CVE-2020-15999?

Upgrade to a fixed version per the vendor advisory; the NVD record lists the affected versions. Use the included PoC to verify your remediation.

Is CVE-2020-15999 actively exploited?

Yes. CVE-2020-15999 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, added 2021-11-03, which means it has been exploited in the wild. CISA set a federal remediation deadline of 2021-11-17. Prioritise patching and deploy the detection and prevention rules above.

For authorized security testing and research only. See the full source and NVD record.