1. Introduction
The AnalogX Proxy SOCKS4a DNS Hostname Handling Remote Overflow vulnerability is a buffer overflow in the remote SOCKS service. An attacker can crash the service by sending a request with a long hostname, potentially disabling it or executing code on the host. This affects systems running an AnalogX proxy server and could lead to denial of service or complete system compromise. Confidentiality, integrity, and availability may be impacted.
2. Technical Explanation
The SOCKS4a service crashes when handling a request containing a hostname longer than the allocated buffer size. An attacker can exploit this by sending a specially crafted SOCKS request with an excessively long hostname to trigger the overflow. This is tracked as CVE-2002-1001. For example, an attacker could send a SOCKS connection request with a hostname exceeding 256 characters to overwhelm the buffer and crash the proxy service.
- Exploit mechanism: An attacker sends a malicious SOCKS connection request containing an oversized hostname, causing a buffer overflow and potentially crashing the service or executing arbitrary code.
- Scope: Affected systems are those running AnalogX Proxy with the SOCKS4a service enabled.
3. Detection and Assessment
To confirm vulnerability, check the proxy version and monitor for crashes during high-load hostname requests.
- Quick checks: Check the AnalogX Proxy server version using its management interface or command line tools if available.
- Scanning: Nessus plugin ID 20394 can detect this vulnerability. This is an example only, and results should be verified.
4. Solution / Remediation Steps
Contact the vendor for a fix to address this vulnerability. Until a patch is available, consider disabling the SOCKS4a service if it’s not essential.
4.1 Preparation
- Ensure you have a rollback plan in place, such as restoring from backup or reverting configuration changes. A change window may be required depending on your environment and impact assessment.
4.2 Implementation
- Step 1: Contact AnalogX support to request the latest patch for this vulnerability.
- Step 2: Download and install the provided patch according to the vendor’s instructions.
4.3 Config or Code Example
Before
After
4.4 Security Practices Relevant to This Vulnerability
Input validation and patch management are key practices for preventing this type of issue. Least privilege can reduce impact if exploited.
- Practice 1: Input validation prevents malicious data from causing crashes or executing code.
- Practice 2: Patching ensures that known vulnerabilities are addressed promptly, reducing the attack surface.
4.5 Automation (Optional)
5. Verification / Validation
Confirm the patch is installed and re-test to ensure the vulnerability is resolved. Monitor logs for any regressions.
- Re-test: Attempt to send a SOCKS connection request with an oversized hostname (e.g., > 256 characters) and verify that the service does not crash or exhibit unexpected behavior.
6. Preventive Measures and Monitoring
Regular security baselines, input validation checks in CI/CD pipelines, and a robust patch management process can help prevent similar issues. For example, update your security baseline to include this vulnerability check.
- Baselines: Update security baselines or policies to require regular patching of AnalogX Proxy servers.
- Pipelines: Implement input validation checks in CI/CD pipelines to block malicious data from reaching the proxy server.
- Asset and patch process: Establish a sensible patch review cycle (e.g., monthly) for critical security updates like this one.
7. Risks, Side Effects, and Roll Back
Patching may cause temporary service disruption or compatibility issues. Roll back to the previous version if problems occur.
- Risk or side effect 1: Patching could temporarily disrupt SOCKS service availability.
- Risk or side effect 2: The patch might introduce compatibility issues with other applications using the proxy server.
8. References and Resources
- Vendor advisory or bulletin: AnalogX Proxy SOCKS4a Overflow Advisory
- NVD or CVE entry: CVE-2002-1001
- Product or platform documentation relevant to the fix: AnalogX Documentation