Static analysis is a technique used to examine and evaluate the source code of a mobile application without executing it. This method is instrumental in identifying potential security vulnerabilities, coding errors, and compliance issues. Static analysis tools can scan the entire codebase automatically, making them a valuable asset for developers and security auditors.
Two good examples of static analysis tools are grep and
semgrep. However, there are many other tools available, and you should choose the one that best fits your needs.
One simple yet effective use of static analysis is using the grep command-line tool to inspect the AndroidManifest.xml file of an Android app. For example, you can extract the minimum SDK version (which indicates the lowest version of Android the app supports) with the following grep command:
grep 'android:minSdkVersion' AndroidManifest.xml This command searches for the android:minSdkVersion attribute within the manifest file. Ensuring a higher minSdkVersion can reduce security risks, as older versions of Android may not include the latest security features and fixes.
semgrep is a more advanced tool that can be used for pattern matching in code. It's particularly useful for identifying complex coding patterns that might lead to security vulnerabilities. For example, to find instances where a deterministic seed is used with the SecureRandom class (which can compromise the randomness and thus the security), you can use a semgrep rule like:
rules: - id: insecure-securerandom-seed patterns: - pattern: new SecureRandom($SEED) - pattern-not: $SEED = null message: "Using a deterministic seed with SecureRandom. Consider using a more secure seed." languages: [java] severity: WARNING This rule will flag any instances in the code where SecureRandom is initialized with a specific seed, excluding cases where the seed is null (which implies a secure random seed).
© OWASP Foundation 2024. This work is licensed under CC-BY-4.0. For any reuse or distribution, you must make clear to others the license terms of this work.
OWASP ® is a registered trademark of the OWASP Foundation, Inc. This website uses cookies to analyze our traffic and only share that information with our analytics partners. Learn more.
