
Understanding Open Source Licenses, Risks, and Compliance
Indrajeet Patil

(xkcd, CC BY-NC 2.5)
Source code for these slides can be found on GitHub
Scope
✅ Inbound FOSS • Using open source in your products
❌ Outbound FOSS • Releasing your code as open source

Disclaimer: Educational purposes only. Not legal advice.
Free Software

Free Software Foundation (1985)
Four Freedoms:
Run, study, modify, share
Open Source
Open Source Initiative (1998)
Open Source Definition:
10 criteria (non-discrimination, license distribution, technology-neutrality)
Different aspects of software are protected by different types of intellectual property law.

Software license: Legal instrument governing use, modification, and distribution of software

| Reciprocal (Copyleft) | Permissive | |
|---|---|---|
| Origin | Free Software Movement | Open Source Initiative |
| Philosophy | Preserve freedom for all users | Maximum freedom to developers |
| Key Feature | Derivatives must use same license | Minimal restrictions |
| Examples | GPL, AGPL, MPL | MIT, BSD, Apache |
| Goal | Ensure software remains free | Enable broad adoption and use |
License Combination Examples:
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=
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Copyleft
Custom
Copyleft
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=
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Permissive
Custom
Any License
License obligations are triggered by distribution
Internal use within your organization is generally NOT distribution
Examples:
IS distribution:
NOT distribution:
Common issues:
Non-compliance consequences:
License changes can break your business:
Major FOSS projects have switched licenses, forcing companies to pay or migrate:
Lesson: Monitor upstream license changes actively!
Famous legal battles involving FOSS license infringement:
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Germany • Dismissed
Linux developer sued VMware for GPL violation. VMware ultimately removed problematic component.
Takeaway: Dismissed cases can still force compliance
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USA • Settled
U.S. court ruled GPL is enforceable contract. Landmark Ghostscript case.
Takeaway: GPL licenses are legally binding contracts
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USA • Multiple Settlements
First U.S. GPL enforcement lawsuits vs. Verizon, Best Buy, Samsung, and others.
Takeaway: Big names aren’t immune to enforcement
Common security risks:
CVEs can enable:

The cost of failing to patch FOSS vulnerabilities:
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Unpatched Apache Struts
150M+ people affected. Patch available 2 months before breach. Cost: $575M settlement.
Takeaway: Delaying patches costs hundreds of millions
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CVSS 10/10 Critical
Apache Log4j vulnerability. CISA: “most serious in my career”. Hundreds of millions of devices vulnerable. Half of corporate networks probed.
Takeaway: Ubiquitous library = ubiquitous vulnerability
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OpenSSL Memory Leak
17% of SSL servers affected (Yahoo, GitHub). Bug existed since 2011, disclosed 2014. Undermined Internet security foundations.
Takeaway: Encryption bugs expose everyone’s secrets
Common sustainability issues:
Business impact:

Critical dependency risk:
FOSS project at your product’s heart = its sustainability is your sustainability
Real-world examples of FOSS sustainability crises:
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Package Removal
11 lines of code, 15M+ downloads. Maintainer removed after dispute, breaking thousands of projects (React, Babel, Node).
Takeaway: Tiny dependencies create massive failure points
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Burnout & Underfunding
9B+ downloads, 50% of top 10k websites. Solo maintainer earns ~$400/month, threatened to go closed-source.
Takeaway: Critical infrastructure runs on volunteer labor
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Maintainer Protest
3.3B+ downloads. Maintainer sabotaged libraries to protest Fortune 500s using free work without giving back.
Takeaway: Frustrated maintainers can become security risks
| Problem | How Automation Helps |
|---|---|
| Hundreds to thousands of direct dependencies | Automated discovery of all FOSS components in codebase |
| Tens of thousands of transitive dependencies | Dependency mapping to track entire dependency tree |
| Multiple package managers (npm, pip, Maven, etc.) | Multi-ecosystem support across all package managers |
| Constantly evolving vulnerability landscape | Continuous monitoring for newly discovered CVEs |
| Unknown license obligations | License detection and compliance checking |
| No visibility into component inventory | SBOM generation (Software Bill of Materials) |
| Manual tracking doesn’t scale | Automated alerts and reporting for issues |
Trivy - Comprehensive security scanner by Aqua Security
Scan a container image:
Free, open-source, widely adopted in CI/CD pipelines

Black Duck by Synopsys - Enterprise-grade SCA platform
Configuration (application.properties):
blackduck.url=https://blackduck.example.com
blackduck.api.token=${BLACKDUCK_TOKEN}
detect.project.name=MyProject
detect.policy.check.fail.on.severities=BLOCKER,CRITICAL
Enterprise support, extensive database, advanced reporting


We’ve seen the risks…
But the answer is YES! ✓
🎨 Frontend
TypeScript • React • Vue
Webpack • Vite • npm
⚙️ Backend
Python • Node.js • Java
FastAPI • Django • Express
💾 Data Layer
PostgreSQL • MySQL • Redis
MongoDB • Kafka • Elasticsearch
☁️ Infrastructure
Docker • Kubernetes • Linux
Terraform • Ansible • Git
You’re already using FOSS everywhere. The question isn’t whether to use it, but how to use it safely.
FOSS is everywhere - Understand what you’re using
Licenses matter - Know the difference between reciprocal and permissive
Distribution triggers obligations - Understand when licenses apply
Security is critical - Don’t be the next Equifax
Automate everything - Use tools like Trivy or Black Duck
Happy FOSSing! 😊
Check out my other slide decks on software development best practices
Free Software Foundation. “What is Free Software?” https://www.gnu.org/philosophy/free-sw.html
Open Source Initiative. “The Open Source Definition.” https://opensource.org/osd
GNU Project. “GNU General Public License v2.0.” https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
Open Source Initiative. “MIT License.” https://opensource.org/licenses/MIT
U.S. House of Representatives. “The Equifax Data Breach Report.” December 2018.
Aqua Security. “Trivy Documentation.” https://aquasecurity.github.io/trivy/
Synopsys. “Black Duck Documentation.” https://synopsys.atlassian.net/wiki/spaces/INTDOCS/
Choose a License. https://choosealicense.com/
TLDRLegal. “Software Licenses in Plain English.” https://www.tldrlegal.com/