Information
The /etc/apt/trusted.gpg.d directory stores individual GPG key files that APT uses to verify the authenticity of packages and repositories.
Solution
Run the following commands to set /etc/apt/trusted.gpg.d Uid and Gid to 0/root and access to 0755 or more restrictive:
# chown root:root /etc/apt/trusted.gpg.d
# chmod u=rwx,g=rx,o=rx /etc/apt/trusted.gpg.d
Impact:
A non-privileged user with write access to /etc/apt/trusted.gpg.d can compromise the chain of trust by adding new public keys to APT trusted keys configuration.