A vulnerability in the TCL Android Smart TV series V8-R851T02-LF1 V295 and below and V8-T658T01-LF1 V373 and below by TCL Technology Group Corporation allows a local unprivileged attacker, such as a malicious App, to read & write to the /data/vendor/tcl, /data/vendor/upgrade, and /var/TerminalManager directories within the TV file system. An attacker, such as a malicious APK or local unprivileged user could perform fake system upgrades by writing to the /data/vendor/upgrage folder.
https://twitter.com/sickcodes/
https://twitter.com/johnjhacking/
https://securityledger.com/2020/11/tv-maker-tcl-denies-back-door-promises-better-process/
https://securityledger.com/2020/11/security-holes-opened-back-door-to-tcl-android-smart-tvs/
https://github.com/sickcodes/security/blob/master/etc/CVE-2020-27403_CVE-2020-28055_GlobalFAQ.pdf