In certain Sonos products before Sonos S1 Release 11.12 and S2 release 15.9, a vulnerability exists in the U-Boot component of the firmware that allow persistent arbitrary code execution with Linux kernel privileges. A failure to correctly handle the return value of the setenv command can be used to override the kernel command-line parameters and ultimately bypass the Secure Boot implementation. This affects PLAY5 gen 2, PLAYBASE, PLAY:1, One, One SL, and Amp.