CVE-2021-29265 : What You Need to Know
Learn about CVE-2021-29265, a critical denial of service vulnerability in the Linux kernel. Understand the impact, affected systems, exploitation mechanism, and mitigation steps.
An issue was discovered in the Linux kernel before 5.11.7. The vulnerability in usbip_sockfd_store in drivers/usb/usbip/stub_dev.c allows attackers to cause a denial of service (GPF) due to race conditions during an update of local and shared status. This vulnerability is identified as CID-9380afd6df70.
Understanding CVE-2021-29265
This section dives into the details of the CVE-2021-29265 vulnerability.
What is CVE-2021-29265?
CVE-2021-29265 is a vulnerability found in the Linux kernel before version 5.11.7. It exists in the USBIP subsystem, specifically in the usbip_sockfd_store function in drivers/usb/usbip/stub_dev.c. Attackers can exploit this vulnerability to trigger a denial of service (GPF) by exploiting race conditions during status updates.
The Impact of CVE-2021-29265
The impact of this CVE is the potential for a denial of service attack, leading to system crashes and instability. By exploiting the race conditions in the usbip_sockfd_store function, attackers can disrupt the normal operation of affected systems.
Technical Details of CVE-2021-29265
This section elaborates on the technical aspects of CVE-2021-29265.
Vulnerability Description
The vulnerability stems from race conditions in the stub-up sequence during updates of the local and shared status within the usbip_sockfd_store function.
Affected Systems and Versions
Systems running Linux kernel versions prior to 5.11.7 are vulnerable to CVE-2021-29265. Specifically, the USBIP subsystem is affected, increasing the risk for systems utilizing USB over IP.
Exploitation Mechanism
To exploit this vulnerability, attackers can leverage the race conditions within the usbip_sockfd_store function to trigger a denial of service condition, resulting in a General Protection Fault (GPF).
Mitigation and Prevention
In this section, we explore the steps to mitigate and prevent exploitation of CVE-2021-29265.
Immediate Steps to Take
It is recommended to update the Linux kernel to version 5.11.7 or newer to mitigate the vulnerability. System administrators should also monitor for any unusual system behavior that may indicate a denial of service attack.
Long-Term Security Practices
To enhance long-term security, organizations should regularly apply security patches, conduct security audits, and stay informed about the latest vulnerabilities and updates within the Linux kernel.
Patching and Updates
Regularly updating the Linux kernel to the latest stable version is essential to address security vulnerabilities like CVE-2021-29265. Organizations should prioritize patching vulnerable systems promptly to prevent potential exploitation.