CVE-2021-35223 : Security Advisory and Response

This article provides details about CVE-2021-35223, a vulnerability in SolarWinds' Serv-U File Server that allows remote code execution using the Execute Command function.

Understanding CVE-2021-35223

This section delves into the impact, technical details, and mitigation strategies related to CVE-2021-35223.

What is CVE-2021-35223?

The Serv-U File Server vulnerability allows for remote code execution by supplying parameters in user string variables during auditing user login failures.

The Impact of CVE-2021-35223

With a CVSS base score of 8.5 (High Severity), this vulnerability has a significant impact on confidentiality, integrity, and availability, requiring immediate attention.

Technical Details of CVE-2021-35223

Details about the vulnerability, affected systems, and exploitation method are discussed here.

Vulnerability Description

The flaw in the Execute Command function of Serv-U File Server permits unauthorized remote code execution through user-controlled parameters.

Affected Systems and Versions

Serv-U versions 15.2.3 and previous are vulnerable to this exploit, with a severity rating of HIGH.

Exploitation Mechanism

By leveraging user string variables to execute a command, threat actors can achieve unauthorized remote code execution on affected systems.

Mitigation and Prevention

Measures to mitigate the impact of CVE-2021-35223 are outlined below.

Immediate Steps to Take

Upgrade to the latest version of Serv-U File Server to eliminate this vulnerability and enhance system security.

Long-Term Security Practices

Regularly update software, conduct security audits, and educate users on safe computing practices to prevent potential threats.

Patching and Updates

SolarWinds recommends immediate software update to patch the vulnerability. If upgrade is not feasible, refer to SolarWinds' Knowledgebase Article for temporary workarounds.