CVE-2025-52435
📋 TL;DR
This vulnerability in Apache NimBLE allows an attacker to downgrade encrypted Bluetooth Low Energy connections to unencrypted state after a Pause Encryption procedure, enabling eavesdropping on subsequent data exchanges. It affects all systems using Apache NimBLE version 1.8.0 or earlier. The vulnerability specifically impacts J2EE applications that rely on NimBLE for Bluetooth communication.
💻 Affected Systems
- Apache NimBLE
📦 What is this software?
Nimble by Apache
⚠️ Risk & Real-World Impact
Worst Case
Sensitive data transmitted over Bluetooth (authentication tokens, personal information, device credentials) is intercepted in plaintext by nearby attackers, leading to data breaches, account compromise, or unauthorized device access.
Likely Case
Attackers within Bluetooth range intercept unencrypted application data, potentially exposing user information, session data, or device telemetry that would normally be protected.
If Mitigated
With proper network segmentation and additional encryption layers, only Bluetooth-specific metadata would be exposed, though the vulnerability still represents a protocol-level security failure.
🎯 Exploit Status
Exploitation requires proximity to target device (Bluetooth range) and ability to trigger/manipulate Pause Encryption procedures. No public exploit code has been identified in references.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.9.0
Vendor Advisory: https://lists.apache.org/thread/ow8dzpsqfh9llfclh5fzh6z237brzc0s
Restart Required: Yes
Instructions:
1. Identify systems using Apache NimBLE
2. Check current version with appropriate package manager or version command
3. Upgrade to version 1.9.0 or later using: git clone https://github.com/apache/mynewt-nimble && cd mynewt-nimble && git checkout 1.9.0
4. Rebuild and redeploy applications using NimBLE
5. Restart affected services/devices
🔧 Temporary Workarounds
Disable Bluetooth when not needed
linuxTurn off Bluetooth functionality on affected devices when not actively required for operation
sudo systemctl stop bluetooth
sudo hciconfig hci0 down
Implement application-layer encryption
allAdd additional encryption at application layer to protect sensitive data even if Bluetooth encryption fails
🧯 If You Can't Patch
- Segment Bluetooth networks from sensitive systems
- Monitor for unusual Bluetooth connection patterns or encryption state changes
🔍 How to Verify
Check if Vulnerable:
Check NimBLE version: grep -r 'NIMBLE_VERSION' in source code or check package version. If version <= 1.8.0, system is vulnerable.Check Version:
grep NIMBLE_VERSION nimble/version.h or check package manager: dpkg -l | grep nimble or rpm -qa | grep nimbleVerify Fix Applied:
Verify version is 1.9.0 or later and check commit history includes fixes 164f1c23c18a290908df76ed83fe848bfe4a4903 and ec3d75e909fa6dcadf1836fefc4432794a673d18📡 Detection & Monitoring
Log Indicators:
- Unexpected Bluetooth encryption state changes
- Multiple Pause Encryption procedure events
- Bluetooth connections dropping from encrypted to unencrypted state
Network Indicators:
- Unencrypted Bluetooth traffic following encrypted sessions
- Abnormal Bluetooth protocol manipulation attempts
SIEM Query:
source="bluetooth_logs" AND (event="encryption_paused" OR event="encryption_disabled")