CVE-2021-39807 : Vulnerability Insights and Analysis

Android NFC vulnerability allowing local privilege escalation.

Understanding CVE-2021-39807

A vulnerability in Android versions 10, 11, 12, and 12L that could enable NFC from the Guest account without proper permission checks.

What is CVE-2021-39807?

Detected in handleNfcStateChanged of SecureNfcEnabler.java
Enables NFC from the Guest account without permission check
Allows local escalation of privilege without additional execution privileges

The Impact of CVE-2021-39807

Potential local escalation of privilege from the Guest account
No user interaction required
Android versions 10, 11, 12, and 12L affected
Android ID: A-209446496

Technical Details of CVE-2021-39807

A deep dive into the technical aspects of the CVE.

Vulnerability Description

Missing permission check in handleNfcStateChanged
Allows enabling NFC from Guest account

Affected Systems and Versions

Product: Android
Versions: Android-10, Android-11, Android-12, Android-12L

Exploitation Mechanism

No additional execution privileges needed
Enables NFC from the Guest account

Mitigation and Prevention

Steps to mitigate and prevent exploitation of CVE-2021-39807

Immediate Steps to Take

Apply security patches from Android
Limit access to vulnerable systems

Long-Term Security Practices

Regular security audits and checks
Enforce the principle of least privilege

Patching and Updates

Stay updated with security bulletins
Apply patches promptly