CVE-2021-20265 : What You Need to Know

This article provides an overview of CVE-2021-20265, a vulnerability found in the Linux kernel which could allow an unprivileged local user to crash the system by depleting available memory.

Understanding CVE-2021-20265

CVE-2021-20265 is a flaw in the Linux kernel that affects system availability by enabling an unprivileged local user to exhaust memory resources. The vulnerability lies in the way memory resources are freed in the unix_stream_recvmsg function when a signal is pending.

What is CVE-2021-20265?

The vulnerability in CVE-2021-20265 allows an unprivileged local user to crash the system by depleting available memory. The flaw can be exploited when a signal is pending, impacting system availability.

The Impact of CVE-2021-20265

The highest risk posed by CVE-2021-20265 is to system availability. An attacker could potentially crash the system by exploiting this vulnerability, leading to denial-of-service conditions.

Technical Details of CVE-2021-20265

CVE-2021-20265 affects Linux kernel version 4.5-rc3. Understanding the vulnerability description, affected systems and versions, as well as the exploitation mechanism, is crucial for mitigating the risk.

Vulnerability Description

The flaw enables an unprivileged local user to crash the system by depleting memory resources during the execution of the unix_stream_recvmsg function when a signal is pending.

Affected Systems and Versions

Linux kernel 4.5-rc3 is the specific version impacted by CVE-2021-20265. Users relying on this version are susceptible to the vulnerability.

Exploitation Mechanism

By leveraging the flaw in the unix_stream_recvmsg function, an unprivileged local user can trigger a system crash by exhausting available memory resources through a pending signal.

Mitigation and Prevention

Understanding how to address CVE-2021-20265 is crucial for maintaining system security and availability.

Immediate Steps to Take

Users are advised to apply relevant patches and updates provided by the Linux kernel maintainers to remediate CVE-2021-20265. Prompt mitigation is essential to prevent exploitation.

Long-Term Security Practices

Implementing secure coding practices, regular security audits, and user privilege management can enhance system resilience against vulnerabilities like CVE-2021-20265.

Patching and Updates

Staying informed about security advisories and promptly applying patches for the Linux kernel is key to ensuring ongoing protection against known vulnerabilities like CVE-2021-20265.