Apktool is a tool for reverse engineering Android APK files. In versions 3.0.0 and 3.0.1, a path traversal vulnerability in `brut/androlib/res/decoder/ResFileDecoder.java` allows a maliciously crafted APK to write arbitrary files to the filesystem during standard decoding (`apktool d`). This is a security regression introduced in commit e10a045 (PR #4041, December 12, 2025), which removed the `BrutIO.sanitizePath()` call that previously prevented path traversal in resource file output paths. An attacker can embed `../` sequences in the `resources.arsc` Type String Pool to escape the output directory and write files to arbitrary locations, including `~/.ssh/config`, `~/.bashrc`, or Windows Startup folders, escalating to RCE. The fix in version 3.0.2 re-introduces `BrutIO.sanitizePath()` in `ResFileDecoder.java` before file write operations.

Aprktool before 2.9.3 on Windows allows ../ and /.. directory traversal.

Apktool is a tool for reverse engineering Android APK files. In versions 2.9.1 and prior, Apktool infers resource files' output path according to their resource names which can be manipulated by attacker to place files at desired location on the system Apktool runs on. Affected environments are those in which an attacker may write/overwrite any file that user has write access, and either user name is known or cwd is under user folder. Commit d348c43b24a9de350ff6e5bd610545a10c1fc712 contains a patch for this issue.