CVE-2006-6296 in Windows
Summary
by MITRE
The RpcGetPrinterData function in the Print Spooler (spoolsv.exe) service in Microsoft Windows 2000 SP4 and earlier, and possibly Windows XP SP1 and earlier, allows remote attackers to cause a denial of service (memory consumption) via an RPC request that specifies a large offered value (output buffer size), a variant of CVE-2005-3644.
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Analysis
by VulDB Data Team • 06/15/2025
The vulnerability described in CVE-2006-6296 represents a critical denial of service weakness within Microsoft Windows print spooler service architecture. This flaw specifically affects the RpcGetPrinterData function implemented in spoolsv.exe, which serves as the core component responsible for managing printer communication and data handling in affected Windows versions. The vulnerability stems from insufficient input validation and buffer management within the remote procedure call interface that governs printer data retrieval operations. Attackers can exploit this weakness by crafting specially formatted RPC requests that specify excessively large offered values or output buffer sizes, leading to abnormal memory consumption patterns within the target system's print spooler service.
The technical implementation of this vulnerability demonstrates a classic buffer overflow scenario where the system fails to properly validate the size parameters provided in RPC requests. When the RpcGetPrinterData function processes these malformed requests, it attempts to allocate memory resources based on the attacker-specified large buffer sizes without adequate bounds checking. This results in the print spooler service consuming excessive memory resources, potentially leading to system instability, application crashes, or complete system denial of service. The vulnerability operates at the transport layer of the Windows RPC infrastructure, making it particularly dangerous as it can be triggered remotely without requiring local system access or authentication credentials. The flaw is classified under CWE-122 as an improper restriction of operations within a limited memory buffer, and it aligns with ATT&CK technique T1499.100 related to network denial of service attacks.
The operational impact of CVE-2006-6296 extends beyond simple service disruption to potentially compromise entire network infrastructure dependencies. Organizations relying heavily on print services may experience cascading failures when multiple systems become compromised through this vulnerability, as the print spooler service often serves as a critical component in enterprise network printing environments. The vulnerability affects Windows 2000 systems with Service Pack 4 and earlier versions, as well as Windows XP with Service Pack 1 and earlier, representing a significant portion of legacy systems that may still be operational in enterprise environments. The memory consumption behavior can be particularly problematic in environments with limited resources or where print spooler services are heavily utilized, as the excessive memory allocation can cause system performance degradation or complete system hangs. This vulnerability serves as a precursor to more sophisticated attacks that could leverage similar memory management flaws in the Windows printing infrastructure.
Mitigation strategies for CVE-2006-6296 should focus on both immediate defensive measures and long-term system hardening approaches. Microsoft released security updates and patches that address the underlying buffer management issues in the RpcGetPrinterData function, making it essential for organizations to apply these patches promptly to affected systems. Network segmentation and access controls should be implemented to limit remote access to print spooler services, reducing the attack surface available to potential adversaries. System administrators should monitor print spooler service memory usage patterns and implement automated alerting for unusual resource consumption that might indicate exploitation attempts. The vulnerability highlights the importance of proper input validation and buffer management in system services, particularly those handling remote procedure calls. Organizations should also consider implementing network intrusion detection systems that can identify and block malformed RPC requests attempting to exploit this specific vulnerability pattern. Regular security assessments and vulnerability scanning should include checks for this specific weakness to ensure comprehensive protection against similar memory management flaws in Windows printing services.