CVE-2021-30355
📋 TL;DR
This vulnerability allows a local attacker with framework user privileges on Amazon Kindle e-readers to escalate to root access. It affects Kindle devices running version 5.13.4 or earlier. The exploit leverages improper privilege management in the system.
💻 Affected Systems
- Amazon Kindle e-reader
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device takeover with root access, allowing installation of malware, data theft, persistence mechanisms, and full control over device functions.
Likely Case
Local privilege escalation enabling unauthorized access to sensitive user data, modification of system files, and potential installation of backdoors.
If Mitigated
Limited impact if device is not physically accessible to attackers and network services are restricted.
🎯 Exploit Status
Exploit requires local access and framework user privileges; detailed technical analysis available from Check Point Research.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 5.13.5 and later
Vendor Advisory: https://www.amazon.com/gp/help/customer/display.html?nodeId=GKMQC26VQQMM8XSW
Restart Required: Yes
Instructions:
1. Connect Kindle to Wi-Fi. 2. Go to Settings → Device Options → Advanced Options → Update Your Kindle. 3. Allow automatic update or manually check for updates. 4. Device will restart after update.
🔧 Temporary Workarounds
Disable USB debugging
allPrevents potential exploitation vectors via USB connection
Settings → Device Options → Advanced Options → Disable ADB
Enable device passcode
allAdds physical access control layer
Settings → Device Options → Device Passcode → Set Passcode
🧯 If You Can't Patch
- Physically secure device to prevent unauthorized access
- Disable all unnecessary services and connectivity options
🔍 How to Verify
Check if Vulnerable:
Check Kindle version: Settings → Device Options → Device Info → Version. If version is 5.13.4 or earlier, device is vulnerable.Check Version:
Settings → Device Options → Device Info → VersionVerify Fix Applied:
After update, verify version is 5.13.5 or later in Settings → Device Options → Device Info → Version.📡 Detection & Monitoring
Log Indicators:
- Unexpected privilege escalation events
- Suspicious process execution as root
- Unauthorized system file modifications
Network Indicators:
- Unusual network traffic from Kindle device
- Unexpected outbound connections
SIEM Query:
event_type:privilege_escalation AND device_type:kindle AND version:<=5.13.4