Despite decades of research, the automatic detection of vulnerabilities in mobile apps remains an open challenge. Among the possible solutions, SAST tools uncover source or compiled code security flaws without needing the app to be executed and tested in a controlled environment. However, SAST tools share several limitations, such as the detection of narrowed vulnerability classes, lack of updates, and limited resiliency to obfuscation techniques. This paper presents SEBASTiAn, a black-box automatic static analysis tool for security vetting Android and iOS apps. It relies on a modular approach to cope with new vulnerabilities.