CVE-2017-0376 Explained : Impact and Mitigation
Learn about CVE-2017-0376, a Tor vulnerability before 0.3.0.8 allowing denial of service attacks. Find out how to mitigate and prevent this security issue.
A vulnerability in Tor before version 0.3.0.8 could lead to a denial of service attack through the hidden-service feature.
Understanding CVE-2017-0376
What is CVE-2017-0376?
Before version 0.3.0.8 of Tor, a vulnerability exists in the hidden-service feature that could be exploited for denial of service. This vulnerability triggers an assertion failure, causing the daemon to exit when a specific cell is sent on a rendezvous circuit.
The Impact of CVE-2017-0376
The vulnerability allows attackers to disrupt Tor services, potentially leading to service unavailability and system instability.
Technical Details of CVE-2017-0376
Vulnerability Description
The vulnerability in Tor before 0.3.0.8 allows a denial of service attack through the hidden-service feature, resulting in an assertion failure and daemon termination.
Affected Systems and Versions
- Product: Tor before 0.3.0.8
- Vendor: Not applicable
- Versions: Tor before 0.3.0.8
Exploitation Mechanism
The vulnerability is exploited by sending a BEGIN_DIR cell on a rendezvous circuit through the connection_edge_process_relay_cell function.
Mitigation and Prevention
Immediate Steps to Take
- Update Tor to version 0.3.0.8 or later to mitigate the vulnerability.
- Monitor network traffic for any suspicious activity that could indicate an ongoing attack.
Long-Term Security Practices
- Regularly update Tor and other software to patch known vulnerabilities.
- Implement network monitoring and intrusion detection systems to detect and respond to potential attacks.
Patching and Updates
Apply security patches and updates provided by Tor Project to address the vulnerability and enhance system security.