An issue was discovered on NOKIA Airscale ASIKA Single RAN devices before 21B. If/when CSP (as a BTS administrator) removes security hardenings from a Nokia Single RAN BTS baseband unit, a directory path traversal in the Nokia BTS baseband unit diagnostic tool AaShell (which is by default disabled) provides access to the BTS baseband unit internal filesystem from the mobile network solution internal BTS management network.