In Unix file system permissions, the "others" category refers to all users except the owner of the file system resource and the members of the group assigned to this resource.

Granting permissions to this category can lead to unintended access to files or directories that could allow attackers to obtain sensitive information, disrupt services or elevate privileges.

Ask Yourself Whether

There is a risk if you answered yes to any of those questions.

Recommended Secure Coding Practices

The most restrictive possible permissions should be assigned to files and directories.

Sensitive Code Example

    public void setPermissions(String filePath) throws IOException {
        Set<PosixFilePermission> perms = new HashSet<PosixFilePermission>();
        // user permission
        perms.add(PosixFilePermission.OWNER_READ);
        perms.add(PosixFilePermission.OWNER_WRITE);
        perms.add(PosixFilePermission.OWNER_EXECUTE);
        // group permissions
        perms.add(PosixFilePermission.GROUP_READ);
        perms.add(PosixFilePermission.GROUP_EXECUTE);
        // others permissions
        perms.add(PosixFilePermission.OTHERS_READ); // Sensitive
        perms.add(PosixFilePermission.OTHERS_WRITE); // Sensitive
        perms.add(PosixFilePermission.OTHERS_EXECUTE); // Sensitive

        Files.setPosixFilePermissions(Paths.get(filePath), perms);
    }

    public void setOthersPermissionsHardCoded(String filePath ) {
        Files.setPosixFilePermissions(Paths.get(filePath), PosixFilePermissions.fromString("rwxrwxrwx")); // Sensitive
    }

Compliant Solution

On operating systems that implement POSIX standard. This will throw a UnsupportedOperationException on Windows.

    public void setPermissions(String filePath) throws IOException {
        Set<PosixFilePermission> perms = new HashSet<PosixFilePermission>();
        // user permission
        perms.add(PosixFilePermission.OWNER_READ);
        perms.add(PosixFilePermission.OWNER_WRITE);
        perms.add(PosixFilePermission.OWNER_EXECUTE);
        // group permissions
        perms.add(PosixFilePermission.GROUP_READ);
        perms.add(PosixFilePermission.GROUP_EXECUTE);
        // others permissions removed
        perms.remove(PosixFilePermission.OTHERS_READ);
        perms.remove(PosixFilePermission.OTHERS_WRITE);
        perms.remove(PosixFilePermission.OTHERS_EXECUTE);

        Files.setPosixFilePermissions(Paths.get(filePath), perms);
    }

    public void setOthersPermissionsHardCoded(String filePath ) {
        Files.setPosixFilePermissions(Paths.get(filePath), PosixFilePermissions.fromString("rwxrwx---"));
    }

See