CVE-2021-33964 : Exploit Details and Defense Strategies

This article provides an overview of CVE-2021-33964, a command injection vulnerability affecting the China Mobile An Lianbao WF-1 V1.0.1 router.

Understanding CVE-2021-33964

CVE-2021-33964 is a critical vulnerability found in the web interface /api/ZRRuleFilter/set_firewall_level of the China Mobile An Lianbao WF-1 V1.0.1 router. This vulnerability allows remote attackers to execute arbitrary commands.

What is CVE-2021-33964?

The China Mobile An Lianbao WF-1 V1.0.1 router is vulnerable to a command injection flaw in the firewall_level parameter of the mentioned web interface. Attackers can exploit this vulnerability to run unauthorized remote commands on the affected system.

The Impact of CVE-2021-33964

The impact of this vulnerability is severe as it allows threat actors to gain unauthorized access to the router, potentially leading to a complete compromise of the device and the network it is connected to.

Technical Details of CVE-2021-33964

This section delves into the technical aspects of CVE-2021-33964, outlining the vulnerability description, affected systems and versions, and the exploitation mechanism.

Vulnerability Description

The vulnerable firewall_level parameter in the /api/ZRRuleFilter/set_firewall_level web interface of the China Mobile An Lianbao WF-1 V1.0.1 router allows for command injection, enabling remote code execution by malicious actors.

Affected Systems and Versions

The China Mobile An Lianbao WF-1 V1.0.1 router is specifically affected by this vulnerability in the firewall_level parameter.

Exploitation Mechanism

Attackers exploit the command injection vulnerability by sending malicious POST requests to the /api/ZRRuleFilter/set_firewall_level interface with crafted firewall_level parameters containing arbitrary commands.

Mitigation and Prevention

To safeguard systems from CVE-2021-33964, immediate steps need to be taken to mitigate the risk and prevent potential exploitation.

Immediate Steps to Take

It is recommended to restrict network access to the vulnerable router, apply vendor-supplied patches if available, or implement network segmentation to contain any potential attacks.

Long-Term Security Practices

In the long term, regular security assessments, firmware updates, and monitoring network traffic for suspicious activities can help prevent and detect command injection vulnerabilities like CVE-2021-33964.

Patching and Updates

Users and administrators are advised to check for security advisories from the vendor regarding patches or updates to address the CVE-2021-33964 vulnerability.