A flaw was found in GLib2. When g_file_replace() is used with G_FILE_CREATE_REPLACE_DESTINATION and creating the .goutputstream-XXXXXX temporary file fails, the library unlinks the destination and recreates it without exclusive creation or symlink protection. A local attacker who can write to the destination directory can win that race and redirect the write to another file.
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