A privilege escalation vulnerability exists in the /bin/login functionality of Peplink Smart Reader v1.2.0 (in QEMU). A specially crafted command line argument can lead to a limited-shell escape and elevated capabilities. An attacker can authenticate with hard-coded credentials and execute unblocked default busybox functionality to trigger this vulnerability.
The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.