From 6634e82cfc46b4126cc2815d364207aae4bcd778 Mon Sep 17 00:00:00 2001
From: Joseph Goydish II <josephgoyd@proton.me>
Date: Thu, 11 Dec 2025 20:06:51 -0500
Subject: [PATCH] Add report on iOS TCC framework bypass vulnerability

Document critical TCC framework flaw in iOS 26.1 allowing unauthorized access to iCloud services by third-party apps. Provide evidence, technical analysis, and recommended remediation actions.
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+# iOS TCC Framework Bypass via Unauthorized auth_reason=5 Grant Mechanism
+
+**Severity:** CRITICAL  
+**Submission Date:** 2025-12-11 UTC  
+**Researcher:** Joseph Goydish II
+
+---
+
+## Executive Summary
+
+Critical TCC framework flaw in iOS 26.1 incorrectly assigns `auth_reason=5` (system bypass authority) to third-party applications, enabling silent access to iCloud services and undocumented telemetry without user consent or Privacy Settings visibility. Analysis of TCC database from iPhone 14 Pro Max reveals 5 unrelated third-party apps with unauthorized system-level grants—evidence indicates framework logic defect, not malicious app behavior. Immediate remediation required: revoke unauthorized grants and fix authorization assignment logic.
+
+**Database:** `sysdiagnose_2025.12.09_13-10-52-0500_iPhone-OS_iPhone_23B85/logs/Accessibility/TCC.db`  
+**SHA256:** `8c6fcd9e7c6ea44d9d2fab262887568978494b35eb298e2a92b0e92b47cef90a`
+
+---
+
+## Evidence: Unauthorized auth_reason=5 Grants
+
+### SQL Query
+```sql
+SELECT client, service, auth_reason, datetime(last_modified, 'unixepoch') as last_modified
+FROM access 
+WHERE auth_reason = 5 AND client NOT LIKE 'com.apple.%' AND client NOT LIKE 'developer.apple.%';
+```
+
+### Third-Party Apps with System Bypass Authority
+
+| Application | Service | Last Modified |
+|-------------|---------|---------------|
+| com.ubercab.UberClient | kTCCServiceUbiquity | 2025-10-24T21:12:37Z |
+| com.linkedin.LinkedIn | kTCCServiceUbiquity | 2025-01-17T04:49:48Z |
+| com.kentoh.hackerfeed | kTCCServiceLiverpool | 2025-09-19T20:56:47Z |
+| com.lifetimefitness.interests.ltfitness | kTCCServiceLiverpool | 2025-05-26T21:34:15Z |
+| com.google.chrome.ios | kTCCServiceWebKitIntelligentTrackingPrevention | 2024-10-25T14:53:03Z |
+
+**Complete dataset:** `TCC_Anomalies_Sanitized.csv` (33 entries)
+
+---
+
+## Technical Analysis & Root Cause
+
+### Framework Logic Flaw
+
+The TCC framework's authorization assignment routine incorrectly evaluates client authority and grants `auth_reason=5` (system bypass) to third-party applications that should only receive `auth_reason=2` (user consent) or `auth_reason=4` (entitlement-based).
+
+**Evidence of framework defect:**
+- Five unrelated apps from different developers with no common functionality or SDK
+- No exploit signatures or privilege escalation code detected
+- Pattern persists across iOS updates (grants span Oct 2024 - Nov 2025)
+
+### Programmatic Grant Characteristics
+
+All unauthorized `auth_reason=5` grants share identical patterns indicating automated framework insertion without user interaction:
+- `pid`: NULL (no process ID recorded)
+- `boot_uuid`: UNUSED (not tied to specific boot session)
+- `last_reminded`: 1970-01-01T00:00:00Z (epoch = never reminded user)
+
+Normal TCC grants include PID, boot UUID, and reminder timestamps. Their absence confirms programmatic auto-grant outside standard consent flow.
+
+### Undocumented Service Access
+
+`kTCCServiceLiverpool`:
+- Not documented in public TCC framework documentation
+- Not visible in iOS Privacy Settings UI
+- Accessed by 87 clients total (19 with `auth_reason=5`)
+- Two third-party apps (HackerFeed, Lifetime Fitness) have unauthorized system bypass to this service
+
+---
+
+## Recommended Remediation
+
+### Immediate Actions
+1. Audit all `auth_reason=5` grants in TCC database; revoke unauthorized third-party app grants
+2. Fix authorization logic: restrict `auth_reason=5` exclusively to Apple-signed system services
+3. Force user re-consent for affected applications via standard TCC prompt flow
+4. Add runtime assertion to detect and reject `auth_reason=5` assignment to non-system clients
+
+### Follow-Up Actions
+5. Implement TCC audit logging: record all `auth_reason=5` assignments with call stack traces
+6. Document `kTCCServiceLiverpool` in public TCC documentation or restrict to system services only
+7. Add Privacy Settings visibility for actual authorization levels (developer mode)
+8. Implement cryptographic binding between `auth_reason` value and client code signature
+
+---
+
+## Reproduction
+
+1. Generate sysdiagnose on iOS 26.1 device
+2. Extract `TCC.db` from `sysdiagnose_*/logs/Accessibility/`
+3. Query: `SELECT client, service FROM access WHERE auth_reason = 5 AND client NOT LIKE 'com.apple.%';`
+4. Expected: Third-party apps listed with system bypass authority (see attached CSV for reference)
+
+---
+
+**End of Report**