CVE-2017-5495 : What You Need to Know

CVE-2017-5495 was published on January 24, 2017, and affects the telnet 'vty' CLI in Quagga versions 0.93 through 1.1.0. This vulnerability allows for unbounded memory allocation, potentially leading to Denial-of-Service attacks.

Understanding CVE-2017-5495

This CVE highlights a critical vulnerability in the telnet 'vty' CLI of Quagga versions 0.93 to 1.1.0, which could be exploited by attackers to trigger a Denial-of-Service attack.

What is CVE-2017-5495?

The vulnerability in the telnet 'vty' CLI of Quagga versions 0.93 to 1.1.0 allows unbounded memory allocation, enabling attackers to launch Denial-of-Service attacks on Quagga daemons or the entire host.

The Impact of CVE-2017-5495

Attackers can exploit this vulnerability without authentication by sending long strings to TCP ports, causing memory allocation issues in Quagga daemons.
The 'vty' input buffer grows indefinitely until the system terminates the daemon or runs out of memory.

Technical Details of CVE-2017-5495

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The telnet 'vty' CLI in Quagga versions 0.93 through 1.1.0 allows unbounded memory allocation, leading to potential Denial-of-Service attacks.

Affected Systems and Versions

All versions of Quagga from 0.93 to 1.1.0 are vulnerable.

Exploitation Mechanism

Attackers can trigger the vulnerability by sending long strings to TCP ports without authentication.

Mitigation and Prevention

Protecting systems from CVE-2017-5495 requires immediate actions and long-term security practices.

Immediate Steps to Take

Upgrade to Quagga 1.1.1 or Free Range Routing (FRR) Protocol Suite 2017-01-10 to resolve the issue.

Long-Term Security Practices

Restrict access to the Quagga telnet interface to local connections only.

Patching and Updates

Ensure timely patching and updates to mitigate the risk of this vulnerability.