CVE-2021-4202 : Vulnerability Insights and Analysis
Learn about CVE-2021-4202, a use-after-free vulnerability in the Linux kernel's NFC Controller Interface that could allow local attackers to escalate privileges. Find out about impacted systems and mitigation steps.
A detailed overview of the use-after-free vulnerability found in NFC Controller Interface (NCI) in the Linux kernel, potentially leading to privilege escalation.
Understanding CVE-2021-4202
This section delves into the specifics of the identified vulnerability.
What is CVE-2021-4202?
CVE-2021-4202 is a use-after-free flaw discovered in nci_request in net/nfc/nci/core.c in NFC Controller Interface (NCI) within the Linux kernel. This flaw could be exploited by a local attacker with user privileges to cause a data race issue during device removal, ultimately resulting in a privilege escalation scenario.
The Impact of CVE-2021-4202
The vulnerability could potentially allow a malicious actor to elevate their privileges on a compromised system by exploiting the data race problem triggered during the device removal process.
Technical Details of CVE-2021-4202
This section explores the technical aspects of CVE-2021-4202.
Vulnerability Description
The use-after-free flaw in nci_request within the Linux kernel's NFC Controller Interface (NCI) can enable a local attacker to manipulate the device removal process, leading to privilege escalation opportunities.
Affected Systems and Versions
The vulnerability affects systems running kernel 5.16 rc2 that have NFC Controller Interface (NCI) enabled.
Exploitation Mechanism
An attacker with user privileges can exploit this flaw by causing a data race issue during the device removal phase, paving the way for privilege escalation.
Mitigation and Prevention
In this section, we discuss the necessary measures to address CVE-2021-4202.
Immediate Steps to Take
Users are advised to implement security patches and updates provided by the Linux kernel maintainers to remediate the vulnerability.
Long-Term Security Practices
Regularly updating the kernel and keeping systems up-to-date with the latest security patches can help mitigate the risk of exploitation.
Patching and Updates
It is crucial for users to apply the relevant patches released by the Linux kernel developers to mitigate the use-after-free vulnerability in the NFC Controller Interface.