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Replacing TripWire with SNMPv3

Matthew G. Marsh

Matthew G. Marsh explores replacing tripwire with snmpv3 at DEF CON 10, examining intrusion-detection and practical defenses.

Summary

Architecture and Background

Marsh - Replacing TripWire with SNMPv3 This talk demonstrates how to use SNMPv3 software (specifically illustrated using Net-SNMP) both with minor custom configurations and also with specialized MIBs and Agents to provide file data and file hashes on demand over secure channels. I also discuss the use of the TCP Inform Trap as a syslog style message transfer mechanism. I spend the majority of the time showing how the authentication and privacy features of SNMPv3 provide robust bi-directional security message transfers.

Vulnerability Analysis

Along the way I demonstrate how to use the split between the authentication and privacy features to provide double blind random file hashes of a managed system. Use of trigger settings to capture file changes will be discussed. I provide the example MIBs and related Agent code for general Unix platforms running Net-SNMP and where possible discuss how to get the code working on Microsoft or other platforms.

Exploitation and Demonstrations

Time permitting I will digress into ways to integrate these techniques into common Network Management platforms. Chief Scientist of the NEbraskaCERT, President & Founder of Paktronix Systems LLC, Author of "Policy Routing Using Linux" (SAMS), Creator of PakSecured Linux. Working in network management and architecture since 1983 specializing in routed IP/IPX/SNA networks.

Remediation and Defensive Strategies

Worked extensively with various SNMP platforms both as a user and as a vendor. On NEAR & BIT -Net in 1984 (PreHistoric Internet) and addicted ever since. As Chief Scientist of the NEbraskaCERT researching IPv4/IPv6/IPSec Integrated Security Networks. Developed the first (and currently still the only) SNMPv3 managable policy routing firewall system for Linux available under GPL at Actively researching management and design of Integrated Security Networks.

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