CVE-2021-3975 : What You Need to Know
Discover the details of CVE-2021-3975, a use-after-free vulnerability in libvirt that could allow attackers to crash the libvirt daemon, impacting systems running vulnerable versions.
A use-after-free vulnerability was discovered in the libvirt library, specifically in the qemuMonitorUnregister() function, which is utilized by multiple threads without proper protection by a monitor lock. This vulnerability could be exploited by an unprivileged attacker to cause a denial of service by crashing the libvirt daemon.
Understanding CVE-2021-3975
This section will cover what CVE-2021-3975 is, its impact, technical details, mitigation, and prevention strategies.
What is CVE-2021-3975?
The CVE-2021-3975 is a use-after-free vulnerability in the libvirt library that could be exploited by an unprivileged attacker to perform a denial of service attack.
The Impact of CVE-2021-3975
The impact of this vulnerability is the potential for a denial of service attack by crashing the libvirt daemon, affecting systems running the vulnerable versions.
Technical Details of CVE-2021-3975
This section will delve into the specific technical aspects of the CVE-2021-3975 vulnerability.
Vulnerability Description
The vulnerability arises from the improper handling of the qemuMonitorUnregister() function in libvirt, allowing for exploitation by an attacker.
Affected Systems and Versions
The vulnerability affects the libvirt library up to version 7.1.0, with the issue being fixed in this specific version.
Exploitation Mechanism
An unprivileged client with a read-only connection could exploit this flaw through the virConnectGetAllDomainStats API when the guest is shutting down.
Mitigation and Prevention
This section focuses on steps to mitigate and prevent exploitation of CVE-2021-3975.
Immediate Steps to Take
It is recommended to update the libvirt library to version 7.1.0 or later to address this vulnerability and prevent potential exploitation.
Long-Term Security Practices
Regularly updating software and implementing security best practices can help prevent similar vulnerabilities in the future.
Patching and Updates
Stay informed about security updates from libvirt and promptly apply patches to ensure your systems are protected.