Delegatecall Vulnerability (Global)
High-quality technical overview of Delegatecall Vulnerability in the context of blockchain security.
Licenses: GPL (Strong), LGPL (Weak), AGPL (Network/Server), Mozilla Public License (MPL). Principles: 1. Freedom to run. 2. Freedom to study. 3. Freedom to redistribute. 4. Freedom to improve and share. Key Difference: Unlike public domain, copyleft work still has an owner but uses that ownership to enforce openness.
graph LR
Center["Delegatecall Vulnerability (Global)"]:::main
classDef main fill:#7c3aed,stroke:#8b5cf6,stroke-width:2px,color:white,font-weight:bold,rx:5,ry:5;
classDef pre fill:#0f172a,stroke:#3b82f6,color:#94a3b8,rx:5,ry:5;
classDef child fill:#0f172a,stroke:#10b981,color:#94a3b8,rx:5,ry:5;
classDef related fill:#0f172a,stroke:#8b5cf6,stroke-dasharray: 5 5,color:#94a3b8,rx:5,ry:5;
linkStyle default stroke:#4b5563,stroke-width:2px;
🧒 5歳でもわかるように説明
Imagine a chef shares a secret recipe for free, but adds one rule: 'You can use this recipe and even change it, but if you give your version to anyone else, you must also share the recipe for free'. You can't start a restaurant and keep the new recipe secret. This rule keeps the recipe available for everyone to improve forever. That's how Copyleft works for computer programs.
🤓 Expert Deep Dive
Technically, copyleft is implemented through a specific set of clauses in a software license, most notably the 'GNU General Public License' (GPL). There are levels of copyleft: 'Strong Copyleft' (like GPL) applies to the entire program if any copylefted code is included, whereas 'Weak Copyleft' (like LGPL) allows linking to copylefted libraries without requiring the main application to be open-sourced. From a business perspective, copyleft is controversial because it prevents 'Proprietary Tivoization'—the practice of using open-source software in a device while using hardware locks to prevent the user from modifying it (which the AGPL v3 specifically forbids). While 'Permissive' licenses (like MIT or Apache 2.0) are more popular in the corporate world for their flexibility, Copyleft remains the primary defense for the 'Commons' of software knowledge.