1. Introduction
The 3com RAS 1500 / Wyse Winterm Malformed Packet Remote Denial of Service vulnerability allows a remote attacker to crash the target host by sending a crafted IP packet with a null length for IP option #0xE4. This can disrupt service availability, potentially impacting business operations that rely on these devices. Systems running affected versions of 3com RAS 1500 or Wyse Winterm are at risk. Impact is high to availability, and low to confidentiality and integrity.
2. Technical Explanation
The vulnerability stems from insufficient handling of malformed IP packets within the 3com RAS 1500 / Wyse Winterm software. An attacker can exploit this by sending a specially crafted packet with an invalid IP option length, leading to a crash. The CVE identifiers associated with this issue are CVE-2005-2577 and CVE-2006-0309.
- Root cause: Improper validation of the IP option length field in incoming packets.
- Exploit mechanism: An attacker sends a TCP packet to the target host with an IP header containing an invalid IP option length (specifically, a null value for option #0xE4). This triggers a crash within the affected software.
- Scope: Affected products are 3com RAS 1500 and Wyse Winterm running vulnerable firmware versions. Specific version details were not provided in the context.
3. Detection and Assessment
Confirming vulnerability requires identifying the installed version of 3com RAS 1500 or Wyse Winterm. A thorough assessment involves network traffic analysis to detect malicious packets.
- Quick checks: Check device configuration interfaces for firmware versions. The method varies by specific model and interface.
- Scanning: Nessus plugin ID 28769 may identify vulnerable systems, but results should be verified manually.
- Logs and evidence: Examine system logs for crash reports or errors related to IP packet processing. Specific log paths will vary depending on the device configuration.
4. Solution / Remediation Steps
Currently, a definitive solution is unknown for this vulnerability. Mitigation focuses on network segmentation and monitoring.
4.1 Preparation
- Stopping services is not required at this time. A roll back plan involves restoring from backup or snapshot.
- Change windows and approvals may be needed depending on organizational policy.
4.2 Implementation
- Step 1: Implement network segmentation to isolate vulnerable devices from critical systems.
- Step 2: Monitor network traffic for suspicious packets targeting the affected hosts.
4.3 Config or Code Example
Before
After
4.4 Security Practices Relevant to This Vulnerability
Network segmentation and intrusion detection are relevant practices for mitigating this vulnerability.
- Practice 1: Network segmentation can limit the impact of a successful exploit by isolating vulnerable devices.
- Practice 2: Intrusion detection systems (IDS) can identify malicious packets targeting affected hosts, providing early warning of an attack.
4.5 Automation (Optional)
No automation is available as no solution exists.
5. Verification / Validation
Verification involves confirming network segmentation and monitoring are in place. A negative test would involve attempting to trigger the vulnerability from a segmented network.
- Post-fix check: Verify that the device is isolated on a separate network segment.
- Re-test: Attempt to send a malformed packet from an isolated network; confirm no crash occurs on critical systems.
- Monitoring: Monitor network logs for suspicious traffic patterns targeting the affected host. Example query: search for packets with invalid IP option lengths.
6. Preventive Measures and Monitoring
Regular security assessments and patch management are important preventive measures.
- Baselines: Update security baselines to include network segmentation requirements for vulnerable devices.
- Pipelines: Implement intrusion detection systems (IDS) in CI/CD pipelines to monitor network traffic for malicious activity.
- Asset and patch process: Establish a regular patch review cycle, although no patch is currently available for this specific vulnerability.
7. Risks, Side Effects, and Roll Back
Network segmentation may disrupt existing connectivity. Roll back involves restoring the original network configuration.
- Risk or side effect 1: Network segmentation could temporarily interrupt service to affected devices. Mitigation: plan changes during a maintenance window.
- Roll back: Restore the original network configuration from backup.
8. References and Resources
Links to relevant resources regarding this vulnerability.
- Vendor advisory or bulletin: No vendor advisory found in context.
- NVD or CVE entry: CVE-2005-2577, CVE-2006-0309
- Product or platform documentation relevant to the fix: No specific documentation found in context.