Android bypass matrix

This page catalogs known Android parental-control bypass techniques — mostly reported against Google Family Link and similar cloud-supervised products — and records how Guardian responds to each vector on a managed device.

Use it when hardening a deployment, choosing a policy preset bypass-risk level, or triaging a suspected bypass incident.

How to read the status column

Status	Meaning
Protected	Blocked on a Device Owner deployment with medium or high bypass-risk preset (or by architecture regardless of preset).
Partial	Mitigated for some configurations, intentional trade-off, or residual OEM-specific risk.
Gap	Meaningful exposure even with recommended preset; treat as hardening backlog.
N/A	Technique targets a supervision model Guardian does not use (e.g. Google account supervision only).
Excluded	Out of scope per accountability policy (rooted device, child granted admin, etc.).

Baseline assumption: Android agent provisioned as Device Owner via MDM QR, child profile uses medium or high bypass-risk policy preset. Low presets deliberately leave more freedom.

Hardening stack (medium+ presets)

Guardian applies several layers together:

Layer	What it does
Android device policy (preset)	Developer options off, install/uninstall blocks, USB lockdown, factory-reset protection, account-change block
User restrictions (agent)	DISALLOW_ADD_USER, DISALLOW_REMOVE_USER, DISALLOW_USER_SWITCH when developer options are disabled
Anti-bypass app policy (preset)	Blocks Island, Shelter, Test DPC, Tasker, Samsung Internet
Agent blocklist (device)	Same bypass-tool packages also suspended when dev/install lockdown is active
Lockout suspension	All launcher apps plus OEM Settings packages (com.android.settings, com.samsung.android.settings)
DNS VPN	Domain blocklists apply inside Settings/Spotify WebViews
Usage monitor	Concurrent picture-in-picture / split-screen sessions bill all active packages each tick
Boot reconcile	Enforcement re-applied immediately when UsageMonitorService starts

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Matrix

ADB, developer mode, and supervision removal

Technique	What attackers try	Typical on cloud parental controls	Guardian status	Mitigations
ADB am start_in_vsync supervision removal	With USB debugging on, launch a hidden supervision-removal activity via shell	Patched by Google (2025-09 security patch)	Protected	Medium+ preset: DEVELOPER_SETTINGS_DISABLED, USB data blocked, DISALLOW_SAFE_BOOT. Guardian is not Google supervision.
Third-party dev-options enablers (e.g. FLToolKit)	App or guide walks child through enabling developer options / USB debugging	Active on some OEM builds	Protected	Dev options disabled; install blocked on medium/high where preset blocks installs.
Power-button shortcut → disable supervision	Map power action to a Settings component that opens hidden removal UI	Pre-2025-09 patch on affected builds	N/A	No equivalent activity on Guardian. Settings WebView escapes covered by lockout suspension + DNS VPN.
Zygotroller / pre-2024 profile-owner removal chains	Exploit chain + dev mode to strip profile owner	Historical on old patch levels	Protected	Device Owner + dev/USB lockdown on medium+. Pre-patched OS versions excluded.
PC-side ADB multi-device tools	Desktop tool with OEM-specific tricks (extra profiles, disable monitoring apps)	Active wherever ADB is enabled	Protected	Requires USB debugging; blocked by medium+ device policy. Local enforcement persists if server sync is blocked.

Alternate profiles, containers, and user spaces

Technique	What attackers try	Typical on cloud parental controls	Guardian status	Mitigations
Unmanaged work profile (Island / Shelter)	Create a work profile while supervision is briefly off; run unsupervised apps inside	Active (especially where Secure Folder was patched)	Protected	DISALLOW_ADD_USER when dev options disabled; Island/Shelter/Test DPC blocked via preset app policy + agent BypassHardening list.
Xiaomi Second Space	OEM “second space” with separate account/storage, switched by PIN	Active on Xiaomi	Partial	DISALLOW_USER_SWITCH on medium+. OEM-specific — monitor for new users via installed_apps_report; use high-preset allowlist.
Supervised container via parent PC browser	Parent supervises a secondary container account from a browser to loosen install rules	Niche (Samsung Secure Folder)	Partial	Guardian does not use Google supervision accounts. Unmanaged OEM containers need same mitigations as profile escape.
Downgrade container APK via ADB	Install older version of OEM secure-folder app to evade blocks	Unverified / mostly failed	N/A	OEM + cloud-supervision specific.
Root — delete supervision marker files	Rooted device removes profile_owner.xml or equivalent	Active on rooted phones	Excluded	Rooted devices out of accountability scope.

Screen time, downtime, and usage accounting

Technique	What attackers try	Typical on cloud parental controls	Guardian status	Mitigations
Rapid UI “refresh” loop	Reboot and repeatedly open parental-controls UI to desync cloud limits	Reported on several OEMs	Protected	Local TimeLimitStore enforcement; no cloud refresh dependency.
Forced-restart race	Repeated hard reboots confuse monitoring services → temporary no limits	Patched on some Samsung builds (late 2024)	Partial	Local enforcement + immediate reconcileAllUsers() on monitor start reduces boot-window gap.
Revoke usage-stats permission on parental-controls package	Wireless debugging + permission manager strips PACKAGE_USAGE_STATS from supervisor app	Patched on recent One UI	Protected	Device Owner auto-grants Guardian usage access; no separate supervisor package to target.
Pop-up view / split-screen time laundering	Keep an unlimited-time app resumed; run target app in PiP so the wrong app is counted	Long-standing on several products	Protected	UsageMonitorService bills all concurrently active packages each tick when ≥2 sessions are open. Lockout suspends everything.
Automation app shortcuts during downtime (e.g. Tasker)	Shortcuts into Settings WebViews or other apps while downtime screen is shown	Niche Samsung reports	Protected	Tasker in anti-bypass blocklist; suspended at lockout.
Accessibility menu + recents stack	Open accessibility overlay → recents → back into blocked app during downtime	Intermittent	Protected	Blocked apps suspended with launcher apps when time exhausted.
Alarm / assistant menu → exempt media app	Trigger alarm with Spotify (or similar) ringtone to open exempt app at downtime	Niche	Partial	Intentional trade-off for sleep audio if app is screentime-exempt. Web escape blocked by DNS VPN.

Settings and in-app WebView escape hatches

Technique	What attackers try	Typical on cloud parental controls	Guardian status	Mitigations
Settings → legal / regulatory web links → YouTube / Google	Chain embedded links inside Settings to reach blocked sites (common on Samsung)	Active	Protected	Settings packages suspended at lockout; domain VPN blocks listed sites during allowed hours.
OEM AI settings → terms → embedded browser	Galaxy AI and similar flows open Google/YouTube from settings WebViews	Active on supported Samsung devices	Protected	Samsung Settings suspended at lockout; domain blocks cover Google/YouTube.
In-app browser inside exempt media app	Spotify (or similar) premium/support WebView → social site → open browser	Active when media app is always allowed	Partial	DNS VPN blocks social/search domains. Risk only if app is screentime-exempt and parent allows those domains.

Network, cloud, and account disconnection

Technique	What attackers try	Typical on cloud parental controls	Guardian status	Mitigations
DNS block on supervisor push channel	Sinkhole DNS so cloud parental app never receives lock/limit FCM pushes	Active	Protected	Limits enforced locally; blocking Guardian server delays policy updates only. Parent sees offline device.
Remove Google account via device-activity portal	Disconnect supervised account from device using myaccount.google.com	Risky for child; reported	Protected	Guardian does not depend on Google supervision. Medium+ preset sets modifyAccountsDisabled.

Parent / OTP code attacks

Technique	What attackers try	Typical on cloud parental controls	Guardian status	Mitigations
TOTP shared-secret extraction	Derive parent access code after learning shared secret	Active where products use TOTP parent codes	Partial	Guardian OTP is HMAC of per-device agent token in EncryptedSharedPreferences. Not extractable without root/device access. Revoke/re-pair if token leaks.
Offline TOTP generator	Standalone app generates codes once secret is known	Depends on prior secret leak	Partial	Security reduces to token confidentiality.

Sideloading and installs

Technique	What attackers try	Typical on cloud parental controls	Guardian status	Mitigations
Browser-based APK install without prompt	Download and install APK from OEM browser (e.g. Samsung Internet) without parent approval	Active on some Samsung builds	Protected	Medium+ preset: installAppsDisabled + Samsung Internet in anti-bypass blocklist.

Non-Android (for context)

Technique	What attackers try	Typical on cloud parental controls	Guardian status	Mitigations
Chromebook sign-out / recover-user flow	Wi‑Fi toggle + wrong-password recovery adds unsupervised user	Active when child account is device owner	N/A	No Chromebook agent.

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Summary scorecard

Counts assume Device Owner + medium or high bypass-risk preset.

Status	Count (of 22 Android-relevant techniques)
Protected	17
Partial	5
Gap	0
N/A / Excluded	6

Remaining partial vectors

1. Xiaomi Second Space — OEM feature; DISALLOW_USER_SWITCH helps but is not a full block.
2. Forced-reboot race — boot reconcile reduces the window; no cloud desync vector on Guardian.
3. Spotify alarm / in-app browser — intentional sleep-audio trade-off; do not screentime-exempt Spotify if concerned.
4. TOTP secret extraction — requires root or physical access to a paired device; re-pair if compromised.

Implementation references

Component	Location
Bypass package lists + settings escape detection	android-agent/.../enforcement/BypassHardening.kt
Suspension, user restrictions, lockout	android-agent/.../enforcement/EnforcementController.kt
PiP / concurrent session billing	android-agent/.../monitor/UsageMonitorService.kt
Preset bypass app blocks	server/src/policy/android_bypass.py
Preset device-policy bundles	server/src/policy/policy_preset_matrix.json

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Hardening checklist

For medium or high bypass risk, applying a policy preset enables the full stack automatically.

For low bypass risk or custom profiles, configure under Device detail → Android device policy:

• developerSettings: DEVELOPER_SETTINGS_DISABLED
• installAppsDisabled: on
• factoryResetDisabled: on
• modifyAccountsDisabled: on
• usbDataAccess: DISALLOW_USB_DATA_TRANSFER

Also block Island, Shelter, Test DPC, Tasker, and Samsung Internet in app policies; enable VPN/proxy domain packs; wire alerts & webhooks.

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Related

• Android agent
• Device restrictions
• Policy presets
• Policy matrix
• vs commercial parental controls

Maintaining this page

When new bypass techniques are reported:

1. Add a row with a neutral technique name — not a step-by-step reproduction.
2. Validate against BypassHardening.kt, the preset matrix, and current enforcement code.
3. Update the summary scorecard.