CVE-2023-43632 : Vulnerability Insights and Analysis

This article provides detailed information about CVE-2023-43632, which involves a vulnerability that allows an attacker to freely allocate a buffer on the stack with data from a socket, leading to system crashes and potential control over the system's vtpm_server process.

Understanding CVE-2023-43632

CVE-2023-43632 is a critical vulnerability identified in EVE OS, affecting versions prior to 9.5.0. The vulnerability arises from the VTPM server listening on port 8877 and exposing limited TPM functionality to clients.

What is CVE-2023-43632?

As described in the eve documentation, the VTPM server in EVE OS allows clients to execute tpm2-tools binaries from specific options. By communicating with this server using protobuf, an attacker can overflow the stack size allocated for a process with controlled data, potentially crashing the system or gaining unauthorized system control.

The Impact of CVE-2023-43632

The impact of CVE-2023-43632 is severe, with a CVSS base score of 9.0, categorizing it as critical. The vulnerability can result in high impacts on confidentiality, integrity, and availability of the affected systems.

Technical Details of CVE-2023-43632

The vulnerability is categorized under CAPEC-100 Overflow Buffers and CWE-789 Memory Allocation with Excessive Size Value.

Vulnerability Description

The vulnerability allows attackers to allocate buffer on the stack using freely controlled data, resulting in system crashes and potential unauthorized system control.

Affected Systems and Versions

EVE OS versions prior to 9.5.0 are affected by this vulnerability, specifically impacting the vtpm_server process.

Exploitation Mechanism

Attackers can crash the system or gain control over the vtpm_server process by overflowing the stack allocated for a relevant process with controlled data.

Mitigation and Prevention

To mitigate the risks associated with CVE-2023-43632, immediate steps should be taken to secure the affected systems and prevent unauthorized access.

Immediate Steps to Take

Update EVE OS to version 9.5.0 or higher to remediate the vulnerability.
Monitor and restrict network access to critical system components.

Long-Term Security Practices

Implement network segmentation and access controls to limit the attack surface.
Regularly update and patch software to address known vulnerabilities.

Patching and Updates

Apply security patches provided by LF-Edge for EVE OS to address CVE-2023-43632 and enhance system security.