CVE 2012-6151
Net-SNMP 5.7.1 and earlier, when AgentX is registering to handle a MIB and processing GETNEXT requests, allows remote attackers to cause a denial of service (crash or infinite loop, CPU consumption, and hang) by causing the AgentX subagent to timeout.
See the 
CVE page on Mitre.org
for more details.
