Ubuntu Security Notice USN-685-1 – Wes Hardaker discovered that the SNMP service did not correctly validate HMAC authentication requests. An unauthenticated remote attacker could send specially crafted SNMPv3 traffic with a valid username and gain access to the user’s views without a valid authentication passphrase. John Kortink discovered that the Net-SNMP Perl module did not correctly check the size of returned values. If a user or automated system were tricked into querying a malicious SNMP server, the application using the Perl module could be made to crash, leading to a denial of service. This did not affect Ubuntu 8.10. It was discovered that the SNMP service did not correctly handle large GETBULK requests. If an unauthenticated remote attacker sent a specially crafted request, the SNMP service could be made to crash, leading to a denial of service.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/72606/USN-685-1.txt
Source: https://packetstormsecurity.com/files/72606/Ubuntu-Security-Notice-685-1.html