What is CVE-2011-2523?

CVE-2011-2523 is a critical security vulnerability affecting vsftpd 2.3.4, a popular FTP server software. The vulnerability is a backdoor that opens a shell on port 6200/tcp, allowing unauthorized access to affected systems. It is important for users and administrators of these systems to be aware of this vulnerability and take appropriate measures to secure their systems.

Who is impacted by this?

The vulnerability specifically impacts vsftpd 2.3.4, as well as Debian Linux 8.0, 9.0, and 10.0. It is crucial for users and administrators of these systems to be aware of this vulnerability and take appropriate measures to secure their systems.

What should I do if I’m affected?

If you're affected by the CVE-2011-2523 vulnerability, it's crucial to take action to secure your system. Here's a simple, step-by-step guide to help you:

1. Update your vsftpd software to a version without the backdoor.

2. Check for updates to the vsftpd software and apply them as necessary.

3. Consider upgrading to a newer, more secure version of vsftpd.

Is this in CISA’s Known Exploited Vulnerabilities Catalog?

The CVE-2011-2523 vulnerability, also known as the vsftpd 2.3.4 backdoor, is not listed in CISA's Known Exploited Vulnerabilities Catalog. It was made public on July 3, 2011, and users are advised to update their vsftpd package to a version without the backdoor vulnerability to secure their systems.

Weakness Enumeration

The weakness enumeration for this vulnerability is categorized as CWE-78, which refers to improper neutralization of special elements used in an OS command, also known as OS command injection.

Learn More

For a comprehensive understanding of this vulnerability, including its description, severity, technical details, and known affected software configurations, refer to the NVD page or the resources listed below.

• Red Hat Customer Portal

• Packet Storm

• Debian Security Tracker