Appwrite is vulnerable to stored cross-site scripting in usernames, function names, storage bucket names, and database collection names.

Appwrite before 2.0.0 contains an argument injection vulnerability that allows authenticated users with functions.write or sites.write permissions to execute arbitrary commands by injecting TAB characters into the providerRootDirectory parameter used to construct GNU tar commands. The application uses escapeshellcmd instead of escapeshellarg and fails to quote the parameter, allowing TAB characters to survive sanitization and be interpreted as argument separators, enabling injection of arbitrary GNU tar arguments such as --checkpoint-action=exec to achieve remote code execution as the builds worker process user.

The ACME-challenge endpoint in Appwrite 0.5.0 through 0.12.x before 0.12.2 allows remote attackers to read arbitrary local files via ../ directory traversal. In order to be vulnerable, APPSTORAGECERTIFICATES/.well-known/acme-challenge must exist on disk. (This pathname is automatically created if the user chooses to install Let's Encrypt certificates via Appwrite.)

In Appwrite CLI before 3.0.0, when using the login command, the credentials of the Appwrite user are stored in a ~/.appwrite/prefs.json file with 0644 as UNIX permissions. Any user of the local system can access those credentials.