A large number of Android manufacturers are skipping security patches but are lying to users about it, a Berlin-based cyber-security firm says. Google releases Android security patches each month in the form of the Android Security Bulletin. One reason for the tardiness or gap in patch delivery may be the chipset (CPU) providers, where one company was often lagging 9-10 patches behind. The SRL team has released an app on the Google Play Store named SnoopSnitch that tells users what patches are missing and if their device is truly up-to-date.
Source: https://www.bleepingcomputer.com/news/security/researchers-catch-android-oems-lying-about-security-patches/