FilePermsFlaws.md

File permission flaws

FileMode parameters (for methods accessing filesystem) are usually provided as octal numbers. This query detects hardcoded FileModes that are not in octal form - numbers you see in the code are not what you will get. The query filters out some commonly used, not-octal integers to reduce number of false positives. Moreover, the query detect calls to permission-changing methods (e.g., os.Chmod, os.Mkdir) when the FileMode has more than 9 bits set - other bits may not be used, depending on the operating system.

Recommendation

Review results and replace highlighted permissions with their octal versions.

Example

package main

import "os"

func main() {
	if len(os.Args) >= 2 {
		if err := os.Chmod(os.Args[1], 644); err != nil {
			return
		}
	}
}

In this example, the call to os.Chmod is most probably not correct - it sets the new directory permissions to 0o1204, and not to the 0644.