CVE-2011-1284 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, Windows Server 2003 SP2, Windows Vista SP1 and SP2, Windows Server 2008 Gold, SP2, R2, and R2 SP1, and Windows 7 Gold and SP1 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 SrvWriteConsoleOutput Vulnerability."
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Analysis
by VulDB Data Team • 11/14/2021
The CVE-2011-1284 vulnerability represents a critical integer overflow flaw within the Client/Server Run-time Subsystem component of Microsoft Windows operating systems. This vulnerability specifically affects Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP1 and SP2, Windows Server 2008 Gold, SP2, R2, and R2 SP1, as well as Windows 7 Gold and SP1. The flaw exists in the Win32 subsystem and manifests through improper handling of memory assignments during user transaction processing within CSRSS.
The technical implementation of this vulnerability stems from an integer overflow condition that occurs when CSRSS processes console output operations through the SrvWriteConsoleOutput function. When a malicious application crafts a specially designed console output request, the subsystem fails to properly validate integer values during memory allocation calculations. This leads to incorrect memory assignment where the system attempts to allocate memory blocks that exceed normal boundaries, resulting in memory corruption. The vulnerability is categorized under CWE-190 as an integer overflow condition, specifically involving signed integer overflow that can be exploited to manipulate memory allocation parameters.
The operational impact of this vulnerability spans both privilege escalation and denial of service scenarios, making it particularly dangerous for system security. Local attackers can leverage this flaw to escalate their privileges from standard user level to system level access, effectively bypassing security controls and gaining unauthorized administrative capabilities. Alternatively, the vulnerability can be exploited to cause system crashes or memory corruption that results in denial of service conditions, disrupting normal system operations and potentially affecting multiple users. The exploitation requires local access to the system and does not require network connectivity, making it particularly concerning for environments where local user access is not strictly controlled.
From a cybersecurity perspective, this vulnerability aligns with ATT&CK technique T1068 which involves the exploitation of legitimate credentials and system privileges to gain elevated access. The vulnerability demonstrates how flaws in core system components can create persistent security risks that affect multiple Windows versions simultaneously. Security researchers have noted that the integer overflow in CSRSS represents a classic example of how improper input validation in kernel-level components can create exploitable conditions. The vulnerability's impact extends beyond immediate privilege escalation as it can serve as a foundation for more sophisticated attacks, potentially enabling attackers to establish persistent backdoors or deploy additional malicious payloads. Organizations should prioritize patch management and system hardening measures to address this vulnerability, as it represents a significant risk to system integrity and confidentiality. The vulnerability underscores the importance of proper memory management practices and input validation in operating system components, particularly those handling user input and system resource allocation.