Multiple Vendor librpc.dll Signedness Error Remote Code Execution Vulnerability

ID ZDI-10-023
Type zdi
Reporter Sebastian Apelt (
Modified 2010-11-09T00:00:00


This vulnerability allows attackers to execute arbitrary code on vulnerable installations of both IBM Informix Dynamic Server and EMC Legato Networker. User interaction is not required to exploit this vulnerability.

The specific flaw exists within the RPC protocol parsing library, librpc.dll, utilized by the ISM Portmapper service (portmap.exe) bound by default to TCP port 36890. During authentication, a lack of a proper signedness check on a supplied parameter size can result in exploitable stack based buffer overflow leading to arbitrary code execution under the context of the SYSTEM user.