CVE-2023-3776 Explained : Impact and Mitigation

This CVE-2023-3776 revolves around a use-after-free vulnerability found in the Linux kernel's net/sched: cls_fw component, allowing attackers to achieve local privilege escalation.

Understanding CVE-2023-3776

This vulnerability, assigned by Google and discovered by Muhammad Alifa Ramdhan of STAR Labs SG, poses a significant risk due to its potential for local privilege escalation.

What is CVE-2023-3776?

The CVE-2023-3776 vulnerability in the Linux kernel's net/sched: cls_fw component allows attackers, upon successful exploitation, to escalate their privileges locally. This arises from a flaw that could lead to a use-after-free scenario.

The Impact of CVE-2023-3776

With a base severity rating of 7.8 (High), this vulnerability has a notable impact on confidentiality, integrity, and availability. The potential for privilege escalation can result in dire consequences if left unaddressed.

Technical Details of CVE-2023-3776

The exploit leverages a flaw in the net/sched: cls_fw component of the Linux kernel to achieve local privilege escalation.

Vulnerability Description

The issue arises when tcf_change_indev() fails, leading to errors in fw_set_parms(). By manipulating the reference counter and setting it to zero, attackers can trigger a use-after-free scenario, facilitating privilege escalation.

Affected Systems and Versions

The affected product is the Kernel by Linux, with versions below 6.5 and specifically version 2.6 being vulnerable to this exploit.

Exploitation Mechanism

Attackers can exploit this vulnerability locally by controlling the reference counter and causing it to be freed, paving the way for escalating their privileges on the system.

Mitigation and Prevention

It is crucial to take immediate action to safeguard systems against the CVE-2023-3776 vulnerability and prevent potential exploitation.

Immediate Steps to Take

Upgrade your systems beyond commit 0323bce598eea038714f941ce2b22541c46d488f to mitigate the risk of this use-after-free vulnerability.

Long-Term Security Practices

Implement robust security measures, such as regular security audits, access controls, and least privilege principles, to enhance overall system security.

Patching and Updates

Stay informed about security updates and patches released by Linux to address this vulnerability promptly. Regularly updating your systems is essential to protect against known vulnerabilities.