CVE-2014-4061 in SQL Server
Summary
by MITRE
Microsoft SQL Server 2008 SP3, 2008 R2 SP2, and 2012 SP1 does not properly control use of stack memory for processing of T-SQL batch commands, which allows remote authenticated users to cause a denial of service (daemon hang) via a crafted T-SQL statement, aka "Microsoft SQL Server Stack Overrun Vulnerability."
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Analysis
by VulDB Data Team • 02/10/2022
The vulnerability identified as CVE-2014-4061 represents a critical stack overrun flaw in Microsoft SQL Server versions 2008 SP3, 2008 R2 SP2, and 2012 SP1. This vulnerability resides in the T-SQL batch command processing mechanism where the system fails to properly enforce stack memory boundaries during command execution. The flaw manifests when authenticated users submit specially crafted T-SQL statements that deliberately exploit memory management weaknesses in the database engine's execution environment.
The technical implementation of this vulnerability stems from insufficient input validation and memory boundary checking within the SQL Server engine's T-SQL interpreter. When processing maliciously constructed T-SQL commands, the system allocates stack memory without adequate safeguards against excessive consumption or improper memory access patterns. This weakness creates a condition where the stack buffer can be overwritten or corrupted, leading to unexpected program behavior and system instability. The vulnerability operates at the kernel level within the database engine's execution context, making it particularly dangerous as it can be triggered through legitimate database connections and authenticated sessions.
From an operational perspective, this vulnerability enables remote authenticated attackers to execute denial of service attacks against SQL Server instances without requiring elevated privileges. The attack vector requires only a valid database login, making it accessible to malicious actors who have gained legitimate access to the database system. When successfully exploited, the vulnerability causes the SQL Server daemon to hang or become unresponsive, effectively rendering the database service unavailable to legitimate users. This disruption can result in significant business impact including application downtime, data unavailability, and potential financial losses due to service interruptions.
The vulnerability maps to CWE-121 Stack-based Buffer Overflow, which classifies it as a memory safety issue where insufficient bounds checking allows attackers to overwrite adjacent memory locations. According to the MITRE ATT&CK framework, this vulnerability aligns with the T1499 technique for Network Denial of Service, as it specifically targets service availability through daemon hang conditions. Organizations should implement immediate mitigations including applying the relevant Microsoft security patches, implementing network segmentation to limit database access, and monitoring for unusual T-SQL command patterns that might indicate exploitation attempts. Additionally, database administrators should consider implementing connection limits and query execution timeouts to reduce the potential impact of such attacks. The vulnerability underscores the critical importance of proper memory management in database engines and highlights the necessity of regular security updates to protect against known exploits in enterprise database systems.