CVE-2021-34550 : What You Need to Know

An in-depth analysis of the vulnerability in Tor before version 0.4.6.5 that allows out-of-bounds memory access through v3 onion service descriptor parsing, leading to a client crash when processing a maliciously crafted onion service descriptor.

Understanding CVE-2021-34550

This section delves into the specifics of the CVE-2021-34550 vulnerability.

What is CVE-2021-34550?

CVE-2021-34550, also known as TROVE-2021-006, is a security flaw found in Tor before version 0.4.6.5. It involves the parsing of v3 onion service descriptors, enabling attackers to trigger out-of-bounds memory access.

The Impact of CVE-2021-34550

The vulnerability poses a risk of a client crash due to the out-of-bounds memory access allowed during the parsing of crafted onion service descriptors.

Technical Details of CVE-2021-34550

Explore the technical aspects of the CVE-2021-34550 vulnerability.

Vulnerability Description

The flaw in Tor before 0.4.6.5 allows attackers to exploit v3 onion service descriptor parsing to execute out-of-bounds memory access, resulting in potential client crashes.

Affected Systems and Versions

All versions of Tor before 0.4.6.5 are affected by CVE-2021-34550, making them vulnerable to the described out-of-bounds memory access issue.

Exploitation Mechanism

By utilizing a carefully crafted onion service descriptor, threat actors can trigger the out-of-bounds memory access vulnerability in v3 onion service descriptors.

Mitigation and Prevention

Learn how to protect systems from the CVE-2021-34550 vulnerability.

Immediate Steps to Take

To mitigate the risk associated with CVE-2021-34550, users should update Tor to version 0.4.6.5 or newer to patch the security flaw.

Long-Term Security Practices

Adopting a proactive approach to security, such as regularly updating software and implementing strong access controls, can help prevent similar vulnerabilities.

Patching and Updates

Maintain vigilance by staying informed about security updates for Tor and promptly applying patches to address known vulnerabilities.