threat-modeling.md

Threat Model Analysis for krallin/tini

Threat: Signal Handling Exploitation

Description: An attacker might craft specific signal sequences or malformed signals to exploit vulnerabilities in tini's signal handling logic. This could involve sending signals designed to trigger buffer overflows, race conditions, or logic errors within tini's signal processing routines. Successful exploitation could lead to unexpected program behavior, crashes, or even arbitrary code execution within the container. Impact: Application instability, Denial of Service, potential container compromise (though less likely due to tini's simplicity). Tini Component Affected: Signal Handling Module (specifically functions related to signal interception, processing, and forwarding like sigaction, kill, signal queue management). Risk Severity: High Mitigation Strategies: * Use stable and actively maintained versions of tini. * Regularly update tini to patch known vulnerabilities. * Monitor tini's logs and behavior for unusual signal handling patterns. * Implement robust error handling in the main application to gracefully handle unexpected termination or signal-related issues, even if caused by tini flaws.

Threat: PID 1 Privilege Abuse via Tini Vulnerability

Description: If a vulnerability exists in tini, an attacker exploiting it gains control within the context of PID 1. While tini is designed to be minimal, any code execution vulnerability at PID 1 within a container is inherently more impactful. An attacker could leverage this to attempt container escape, privilege escalation within the container, or perform container-wide Denial of Service. Impact: Critical - Container compromise, privilege escalation, Denial of Service. Tini Component Affected: Any component of tini that contains a vulnerability (e.g., memory management, input parsing, signal handling). Risk Severity: Critical Mitigation Strategies: * Prioritize using the latest stable and security-patched version of tini. * Conduct regular security audits and vulnerability scanning of container images, including tini. * Implement strong container security practices in general to limit the blast radius of any container compromise. * Employ security monitoring and intrusion detection systems to detect and respond to suspicious activity within containers.

Threat: Supply Chain Compromise of Tini Binary

Description: An attacker could compromise the supply chain of tini by injecting malicious code into the build process or distribution channels. This could result in users unknowingly using a backdoored or vulnerable version of tini in their container images. A compromised tini could perform malicious actions from within the container, potentially undetected. Impact: High - Full container compromise, data exfiltration, malicious activity, long-term persistent access. Tini Component Affected: Entire tini binary and build/distribution infrastructure. Risk Severity: High Mitigation Strategies: * Obtain tini binaries from trusted and verified sources (official GitHub releases, reputable package registries). * Verify the integrity of downloaded tini binaries using checksums or cryptographic signatures provided by the tini maintainers. * Implement secure container image build pipelines with supply chain security best practices. * Regularly scan container images for known vulnerabilities and signs of tampering. * Consider using binary transparency and provenance tools if available for tini or container base images.