By sending a specially malformed management request to a system running an affected version of the SNMP service, an attacker could cause a denial of service. In addition, it is possible that he could cause code to run on the system in LocalSystem context. This could potentially give the attacker the ability to take any desired action on the system.
The vulnerability results because the component of the SNMP agent service that parses incoming commands contains an unchecked buffer. By sending a specially malformed request, it could be possible to conduct a buffer overrun attack against an affected system.
Download this patch to prevent hackers from launching a denial of service attack or running malicious code on your Windows 98 system.