CVE-2021-3905 : What You Need to Know

A memory leak vulnerability was discovered in Open vSwitch (OVS) that could be exploited by an attacker to exhaust available memory through userspace IP fragmentation processing.

Understanding CVE-2021-3905

This section provides insights into the impact, technical details, and mitigation strategies related to CVE-2021-3905.

What is CVE-2021-3905?

The CVE-2021-3905 vulnerability involves a memory leak in Open vSwitch (OVS) during userspace IP fragmentation processing. Attackers could potentially consume all available memory by continuously sending packet fragments.

The Impact of CVE-2021-3905

This vulnerability could lead to a denial of service (DoS) condition due to memory exhaustion, affecting the availability and performance of systems running the vulnerable OVS versions.

Technical Details of CVE-2021-3905

This section delves into the specifics of the vulnerability, affected systems, and the exploitation mechanism.

Vulnerability Description

The memory leak in OVS allows an attacker to trigger memory exhaustion by sending fragmented packets, thereby disrupting system operations.

Affected Systems and Versions

Open vSwitch (OVS) versions prior to v2.17.0 are impacted by this vulnerability. Systems running these versions are at risk of memory depletion attacks.

Exploitation Mechanism

An attacker can exploit CVE-2021-3905 by continuously sending fragmented packets to the vulnerable OVS instances, gradually depleting system memory resources.

Mitigation and Prevention

In this section, we discuss immediate steps to take and long-term security practices to mitigate the risks associated with CVE-2021-3905.

Immediate Steps to Take

Update to Open vSwitch version 2.17.0 or newer to apply the fix for the memory leak vulnerability.
Implement network monitoring to detect unusual traffic patterns indicative of memory depletion attacks.

Long-Term Security Practices

Regularly update OVS and other software components to address security vulnerabilities promptly.
Conduct security assessments and penetration testing to uncover potential weaknesses in the network infrastructure.

Patching and Updates

Stay informed about security advisories from OVS and other relevant sources to promptly apply patches and updates that address known vulnerabilities.