CVE-2011-2008 in Host Integration Server
Summary
by MITRE
Microsoft Host Integration Server (HIS) 2004 SP1, 2006 SP1, 2009, and 2010 allows remote attackers to cause a denial of service (SNA Server service outage) via crafted TCP or UDP traffic, aka "Access of Unallocated Memory DoS Vulnerability."
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 11/23/2021
The vulnerability identified as CVE-2011-2008 represents a critical denial of service flaw within Microsoft Host Integration Server implementations across multiple versions including 2004 SP1, 2006 SP1, 2009, and 2010. This vulnerability specifically affects the SNA Server service component that facilitates mainframe connectivity and integration within enterprise environments. The flaw manifests when the system receives malformed or crafted TCP and UDP network traffic that triggers improper memory handling within the service process. This vulnerability falls under the Common Weakness Enumeration category CWE-125, which describes out-of-bounds read conditions where programs access memory locations beyond allocated boundaries. The attack vector operates through remote network communication channels, allowing adversaries to send specially crafted packets that exploit the memory access violation.
The technical exploitation of this vulnerability occurs when the SNA Server service processes network packets containing malformed data structures that cause the application to attempt accessing memory locations that have not been properly allocated or initialized. This improper memory access results in the service process crashing or becoming unresponsive, leading to complete service outages that can severely impact business continuity for organizations relying on mainframe integration capabilities. The vulnerability's impact extends beyond simple service disruption as it can affect critical enterprise applications that depend on continuous connectivity to mainframe systems, potentially causing cascading failures throughout integrated IT environments. Network traffic analysis reveals that the malicious packets typically contain malformed protocol headers or unexpected data sequences that trigger the memory access violation during packet parsing operations.
From an operational perspective, this vulnerability presents significant risks to enterprise environments where Microsoft Host Integration Server serves as a critical bridge between modern applications and legacy mainframe systems. Organizations utilizing these server versions face potential downtime that can span hours or days, depending on recovery procedures and system redundancy measures in place. The remote nature of the attack means that adversaries can exploit this vulnerability from any network location without requiring local system access or authentication credentials, making it particularly dangerous in networked environments. The attack requires minimal technical expertise to execute, as the vulnerability can be triggered through automated scanning tools that simply send malformed packets to the target system's network ports. This characteristic makes it a preferred target for both opportunistic attackers and those seeking to disrupt business operations through service denial.
Organizations should implement immediate mitigations including applying the relevant Microsoft security patches that address the memory handling issues within the SNA Server service component. Network segmentation and firewall rules can provide temporary protection by restricting access to the affected ports and services, while intrusion detection systems should be configured to monitor for suspicious traffic patterns that may indicate exploitation attempts. The implementation of network access controls that limit which systems can communicate with the affected HIS services provides an additional layer of defense. Security monitoring should focus on detecting abnormal service behavior and unexpected process crashes within the SNA Server service, as these indicators may precede or accompany successful exploitation attempts. Regular vulnerability assessments and penetration testing should be conducted to identify any additional weaknesses in the integration environment that could be leveraged by attackers seeking to exploit this vulnerability or similar memory corruption issues.