Xiaomi Watch S2

Xiaomi Watch S2
Security Grade B Calculator v1	Xiaomi Watch S2 Brand: Xiaomi (Parent: Xiaomi Corporation) Category: Smartwatch • Model / Gen: Second Generation (S Series) M2225W1, M2226W1 Release Date: 2022-12-11 • Status: End of sale Classification Date: 2025-10-10 • Official Website

Security Evaluation

1. Device Security

Criterion	Value	Proof	Comment
Known hardware tampering	None	—
Known vulnerabilities	Rare	[General wearable security advisories 🔗 Proof]	Potential vulnerabilities typically related to Bluetooth pairing or companion app.
Prior attacks	None	—
Updatability	Very common	[Firmware updates via Xiaomi Wear app 🔗 Proof]	Receives firmware updates for features and security through the companion app.
Category Score	Score: 2 / 3

2. System Security

Criterion	Value	Proof	Comment
Authentication with other systems	Partial	[Xiaomi Wear app functionality 🔗 Proof]	Pairs with smartphone via Bluetooth for data sync and notifications
Communications	Encrypted with up-to-date encryption	[Uses standard Bluetooth encryption protocols 🔗 Proof]
Storage	No encryption	[Nature of wearable device data storage 🔗 Proof]	Typically stores limited, non-sensitive data locally; sensitive data stored on paired phone.
Category Score	Score: 2 / 3

3. User Authentication

Criterion	Value	Proof	Comment
Account management	Basic	[Xiaomi account integration via app 🔗 Proof]
Authentication	Basic	[Product manual 🔗 Proof]	Unlocks when paired/connected to phone. May offer simple screen lock pattern.
Brute-force protection	Basic	[Limited by simple interface 🔗 Proof]	Lacks sophisticated lockout mechanisms due to limited input methods.
Event logging	Access event logged	[Device interface and app 🔗 Proof]	No user-accessible event logging for authentication attempts on the watch itself.
Passwords	Default/Common/Easy to guess	—
Category Score	Score: 2 / 3

Technical Specifications

Property	Details
Operating System & App	Proprietary RTOS (Managed by Xiaomi HyperOS ecosystem) (Companion App: Xiaomi Wear (Previously Mi Fitness))
Hardware (CPU / GPU)	CPU: BES2500BP • GPU: Integrated
Memory & Storage	Memory: 2GB RAM (approx.) • Storage: 32GB ROM (approx.)
Power, Battery & Charging	Battery: 42mm: 305 mAh; 46mm: 500 mAh • Power: Magnetic charging puck • Charging: Wired magnetic charging, typical full charge in about 2 hours
Display & Camera	Display: 1.32-inch (42mm) / 1.43-inch (46mm), AMOLED, 466 x 466 resolution, Always-On Display support • Camera: No
Sound & Connectivity	Sound: Built-in microphone and speaker • Connectivity: Bluetooth 5.2, NFC (region dependent)
Physical (Dimensions & Mass)	Dimensions: 42mm: 42.3 x 42.3 x 11.4 mm; 46mm: 46.5 x 46.5 x 11.4 mm • Mass: 42mm: ~37g (without strap); 46mm: ~52g (without strap)