Appium is a cross-platform automation framework for all kinds of apps, built on top of the W3C WebDriver protocol. Prior to 7.2.6, @appium/support ZIP extraction accepts an archive entry that creates a symbolic link to a location outside the extraction directory and then accepts a later regular-file entry whose legitimate name resolves through that link. The lexical containment check examines entry names without validating the symlink target or the real destination, so an attacker-controlled archive can write files to arbitrary locations writable by the Appium process. This is distinct from the earlier parent-directory entry-name traversal fixed in 7.0.6 because the bypass uses no parent-directory or absolute entry name. Depending on the writable destination, the arbitrary file write can overwrite configuration, startup scripts, or executables and lead to code execution. This issue is fixed in version 7.2.6.
Weakness
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.
Potential Mitigations
- Follow the principle of least privilege when assigning access rights to entities in a software system.
- Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/132.html
- https://cwe.mitre.org/data/definitions/17.html
- https://cwe.mitre.org/data/definitions/35.html
- https://cwe.mitre.org/data/definitions/76.html