Xiaomi Redmi Watch 5 Active

Xiaomi Redmi Watch 5 Active
Security Grade D Calculator v1	Xiaomi Redmi Watch 5 Active Brand: Xiaomi (Redmi sub-brand) (Parent: Xiaomi Corporation) Category: Smartwatch / Wearable • Model / Gen: Redmi Watch 5 series (Active variant) Redmi Watch 5 Active Release Date: 2024-08-27 • Status: In sale Classification Date: 2026-10-27 • Official Website

Security Evaluation

1. Device Security

Criterion	Value	Proof	Comment
Known hardware tampering	Rare	🔗 Proof	The Redmi Watch 5 Active runs RT-Thread RTOS on an ARM Cortex-M33 (SiFli SF32LB551), not Android/Wear OS, which removes standard fastboot/adb interfaces. However, the Byterialab research repository demonstrates full firmware dump and reverse engineering via crafted watchface files that trigger out-of-bounds (OOB) memory reads, and the repository includes a watchface payload generator and pre-built OOB/DoS payloads. This is a software-level firmware access path, not a hardware bootloader unlock. No official bootloader-unlock method is provided by Xiaomi. “Rare” reflects the high barrier (no official unlock) while acknowledging a publicly documented firmware-access research path.
Known vulnerabilities	Very common	https://dtic.dimensions.ai/details/publication/pub.1201392493 🔗 Proof	This is the strongest evidence-backed rating for this device. The Byterialab repository publicly documents out-of-bounds (OOB) memory reads triggered by malformed watchface files, plus DoS payloads and SSL-pinning bypass scripts for the Mi Fitness app. Separately, a peer-reviewed security case study (published in the Companion Proceedings of the ACM Web Conference 2025) tested the Redmi Watch 5 Active against the Amazfit GTS 4 and found that the Redmi “only meets basic requirements and relies on the user’s initiative in several areas” regarding access security, brute-force resistance, Bluetooth communication security, and update mechanisms. The existence of a public vulnerability research repository and an independent academic security assessment justifies “Very common”.
Prior attacks	Rare	🔗 Proof	The public record consists of security research and proof-of-concept payloads (OOB reads, DoS), not reports of large-scale in-the-wild attacks targeting Redmi Watch 5 Active users. The Byterialab repository is a research disclosure, not an exploit-kit distribution. No public incident report of active, targeted attacks against this model has been identified. “Rare” reflects the absence of observed attack activity despite the documented vulnerability surface.
Updatability	Rare	https://dtic.dimensions.ai/details/publication/pub.1201392493 🔗 Proof	Xiaomi does not publish a formal, binding security-update cadence or end-of-support date for the Redmi Watch 5 Active. The ACM Web Conference 2025 case study explicitly evaluated “update mechanisms” as one of the tested dimensions and found the device’s protection to be basic, relying on user initiative. The device runs RT-Thread RTOS, not Android/Wear OS, so it does not inherit Google’s monthly Android security-patch framework. No equivalent of OnePlus/Samsung’s published multi-year quarterly patch commitment exists for this model. “Rare” reflects maintenance capability without a published, binding schedule.
Category Score	Score: 3 / 3

2. System Security

Criterion	Value	Proof	Comment
Authentication with other systems	Partial	🔗 Proof	The watch pairs with Android and iOS via the Mi Fitness app and supports Alexa integration. However, unified SSO across third-party identity providers (enterprise IdPs, Google, Microsoft) is not a native “Full” capability. Authentication is scoped to the Xiaomi/Mi Fitness ecosystem, with partial bridging to Alexa and standard Bluetooth protocols.
Communications	Encrypted with up-to-date encryption	🔗 Proof	The ACM Web Conference 2025 case study specifically tested “security of Bluetooth communication” between the watch and paired devices. While the study found overall protection to be basic, it did not report a broken or obsolete encryption protocol; the finding was that the device “only meets basic requirements” and relies on user initiative, not that it uses known-broken cryptography. The device uses Bluetooth 5.3, which supports modern LE Secure Connections. “Encrypted with up-to-date encryption” is the defensible baseline, with the caveat that the implementation is basic rather than hardened.
Storage	Encrypted with up-to-date encryption	🔗 Proof	The same case study evaluated “management of personal and health data” on the device. It found the protection level to be basic, but did not report that data is stored unencrypted or with obsolete encryption. As an RTOS wearable, the device is not subject to Android’s mandatory FBE baseline, so this rating should be treated as vendor-claimed or case-study-inferred, not as a confirmed implementation of a specific modern cipher. If the Wiki requires a named cryptographic standard (e.g., AES-256), this rating may need to be downgraded pending vendor confirmation.
Category Score	Score: 2 / 3

3. User Authentication

Criterion	Value	Proof	Comment
Account management	Basic	🔗 Proof	The watch pairs with the Mi Fitness app and a Xiaomi account for data sync and management. As a wearable, its account lifecycle is dependent on the paired phone and the Xiaomi/Mi Fitness account system; it does not provide the full standalone account-management surface of a smartphone or PC.
Authentication	Basic	🔗 Proof	The ACM Web Conference 2025 case study tested “access security” and “resistance to brute-force attacks” on the Redmi Watch 5 Active and found that it “only meets basic requirements and relies on the user’s initiative in several areas”. The watch does not feature biometric authentication (no fingerprint, no 3D face); unlock relies on the paired device. “Basic” accurately reflects this capability tier.
Brute-force protection	Basic	🔗 Proof	The same case study explicitly tested “resistance to brute-force attacks” and classified the Redmi Watch 5 Active’s protection as basic, relying on user initiative rather than a hardened, enforced lockout policy. This is a direct, peer-reviewed citation supporting “Basic” rather than “Exist”.
Event logging	Partial logging	[RT-Thread RTOS platform behavior 🔗 Proof]	The watch records basic access and health-data events (workout logs, health measurements, notification access), but its event-logging surface is limited compared with a smartphone or PC. No public documentation describes a comprehensive, user-accessible security audit log on the device.
Passwords	Default/Common/Easy to guess	🔗 Proof	The case study’s finding that the device “relies on the user’s initiative in several areas”, combined with the absence of enforced complexity or periodic-change policies for the watch credential, supports the most conservative rating. The watch does not enforce a full account-password policy with complexity requirements; unlock depends on the paired device’s PIN/pattern. “Default/Common/Easy to guess” reflects the credential type and the lack of enforced complexity, not a specific known weak default.
Category Score	Score: 3 / 3

Technical Specifications

Property	Details
Operating System & App	RT-Thread RTOS (ARM Cortex-M33; not Android/Wear OS) (Companion App: Mi Fitness (requires background location permissions for syncing))
Hardware (CPU / GPU)	CPU: SiFli SF32LB551 (ARM Cortex-M33) • GPU: Not applicable / not published
Memory & Storage	Memory: Not publicly specified in official materials • Storage: Not publicly specified in official materials
Power, Battery & Charging	Battery: 470 mAh; up to 18 days typical usage • Power: Magnetic charging • Charging: Magnetic pin charging
Display & Camera	Display: 2.0-inch IPS LCD, 320 × 385, 60 Hz refresh rate • Camera: None
Sound & Connectivity	Sound: Built-in speaker and triple-microphone with ENC (for Bluetooth calling) • Connectivity: Bluetooth 5.3, 5ATM water resistance
Physical (Dimensions & Mass)	Dimensions: 49.10 mm (case diameter, without SIM) • Mass: Not consistently published in official spec summaries

Classification target is Xiaomi Redmi Watch 5 Active. The most material evidence is the Byterialab GitHub repository (published 2026-02-11), which documents OOB memory reads via crafted watchface files, DoS payloads, and SSL-pinning bypass scripts for the Mi Fitness app, and the ACM Web Conference 2025 case study that independently tested the device’s access security, brute-force resistance, Bluetooth security, and update mechanisms and found it “only meets basic requirements and relies on the user’s initiative.” The device runs RT-Thread RTOS on ARM Cortex-M33, not Android/Wear OS, which changes the hardware-tampering and update-policy assessment logic. Authentication = Basic and Brute-force protection = Basic are directly supported by the case study’s findings. Updatability = Rare because Xiaomi has not published a binding security-update cadence, and the case study’s update-mechanism testing found the protection to be basic.