config-file-parsing-bugs

What problem does it solve?

Config file parsers often have undocumented quirks that cause silent truncation, overwriting, or misinterpretation of values, leading to critical security vulnerabilities when parsed values are used for access control or service configuration decisions.

Core Features & Use Cases

• Line Truncation Exploitation: Leverage fixed-size fgets() buffer flaws in C-based parsers like inih and PAM to inject malicious config entries.
• Duplicate Key Overwrite Attacks: Exploit last-key-wins behavior in INI, YAML, and TOML parsers to override legitimate configuration values.
• Parser Quirk Detection: Identify encoding differentials, whitespace handling issues, and environment variable interpolation flaws that lead to unexpected parsing results.
• Use Case: A red teamer can use this skill to bypass application authentication by injecting an admin=true entry into a truncated INI config line, which the parser interprets as a legitimate configuration value.

Quick Start

Use the config-file-parsing-bugs skill to test the target application's INI and YAML config parsers for truncation and overwrite vulnerabilities.