Tech Stack

• Affected Technology: Apache Traffic Server (ATS)

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Date(s) Issued

• Publication Date: November 11, 2016
• Last Modified Date: N/A (refer to current sources for updated information if needed)

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Criticality

• CVSS Score: 5.3 (Medium)
  • Impact: Denial of Service (DoS)
  • Attack Vector: Network

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Overview

CVE-2016-8735 is a vulnerability in Apache Traffic Server that can be exploited to cause a Denial of Service (DoS) condition. The issue arises from improper handling of certain HTTP/1.1 requests. An attacker could exploit this flaw by sending specially crafted HTTP requests to a vulnerable server, leading to resource exhaustion and service unavailability.

Affected versions:

• Apache Traffic Server versions prior to 6.2.1.

Potential impact:

• Disruption of normal service, rendering web traffic inaccessible.
• Possible resource exhaustion affecting other hosted services.

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Solution/Mitigation

1. Upgrade Apache Traffic Server
   • Upgrade to Apache Traffic Server version 6.2.1 or newer, as this version resolves the vulnerability.
   • Refer to the official Apache Traffic Server download page for the latest stable release.
2. Restrict Untrusted Access
   • Limit access to the ATS management interface and HTTP services to trusted networks using firewalls or Access Control Lists (ACLs).
   • Apply configurations to only allow requests from known, trusted sources.
3. Rate Limiting
   • Implement rate limiting for incoming HTTP requests to mitigate the impact of potential exploitation.
   • Configure server settings to handle abusive patterns and throttling.
   Example rate-limiting configuration:arduinoCopy codeCONFIG proxy.config.http.global_user_agent_polling_frequency INT <value>
4. Monitoring and Logging
   • Enable and review detailed logs to identify malicious or unusual HTTP request patterns.
   • Use log analysis tools to monitor for high request rates or malformed HTTP requests indicative of potential exploitation attempts.
5. Apply Patches
   • Ensure other components of the server infrastructure are up-to-date with security patches.
   • Regularly check the Apache Traffic Server Security page for the latest advisories and patches.

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Confirmation & Additional Information

Verification:

After upgrading, verify the version using the command:cssCopy codetraffic_server --version

Conduct stress tests to ensure system stability under high loads.

Staying Updated:

Subscribe to Apache Traffic Server mailing lists for announcements on security updates.

Regularly audit server configurations for compliance with best practices.

Additional Resources:

National Vulnerability Database: CVE-2016-8735