CVE-2011-1870 in Windows
Summary
by MITRE
Integer overflow in the Client/Server Run-time Subsystem (aka CSRSS) in the Win32 subsystem in Microsoft Windows XP SP2 and SP3, and Windows Server 2003 SP2, allows local users to gain privileges or cause a denial of service (memory corruption) via a crafted application that triggers an incorrect memory assignment for a user transaction, aka "CSRSS Local EOP SrvWriteConsoleOutputString Vulnerability."
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 11/14/2021
The CVE-2011-1870 vulnerability represents a critical integer overflow flaw within the Client/Server Run-time Subsystem (CSRSS) component of Microsoft Windows operating systems. This vulnerability specifically affects Windows XP SP2 and SP3, as well as Windows Server 2003 SP2, making it a persistent threat across multiple server and desktop environments. The CSRSS process serves as a fundamental component in the Windows Win32 subsystem, responsible for managing user sessions and console operations, which makes this vulnerability particularly dangerous as it operates at a core system level.
The technical exploitation of this vulnerability occurs through an integer overflow condition that manifests when a malicious application triggers incorrect memory assignment during user transaction processing. This flaw specifically affects the SrvWriteConsoleOutputString function within CSRSS, where the system fails to properly validate integer values before performing memory operations. The overflow results in improper memory allocation that can lead to memory corruption, creating opportunities for privilege escalation or system instability. According to CWE classification, this vulnerability maps to CWE-190, which describes integer overflow conditions that can result in memory corruption and arbitrary code execution. The underlying mechanism involves the system's failure to properly handle large integer values that exceed the maximum representable value for the target data type, leading to unexpected behavior in memory management operations.
The operational impact of CVE-2011-1870 extends beyond simple denial of service scenarios to encompass potential privilege escalation capabilities that could allow local attackers to elevate their system privileges. Attackers can leverage this vulnerability to execute malicious code with elevated privileges, potentially gaining full system control or accessing sensitive data. The memory corruption resulting from the integer overflow can manifest as system crashes, application instability, or more sophisticated exploitation techniques that bypass standard security controls. From an ATT&CK framework perspective, this vulnerability aligns with techniques such as privilege escalation through kernel exploits and process injection methods, making it particularly concerning for enterprise security environments where local access might be obtained through various attack vectors.
Mitigation strategies for this vulnerability require immediate patch application through Microsoft's security updates, as the flaw exists in legacy Windows versions that may not receive continued support. Organizations should implement comprehensive patch management procedures to ensure all affected systems receive the necessary security updates. Additionally, system hardening measures including disabling unnecessary services, implementing least privilege principles, and monitoring for anomalous console operations can help reduce the attack surface. Network segmentation and access controls should be strengthened to limit potential exploitation paths, while security monitoring solutions should be configured to detect unusual memory allocation patterns or process behavior that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of maintaining up-to-date security patches and understanding the attack surface of core system components like CSRSS that handle fundamental user session management operations.