A significant security flaw has been identified in Microsoft SQL Server, designated as CVE-2025-49719. This vulnerability allows unauthorized attackers to access sensitive data over network connections without requiring authentication or user interaction. The issue arises from improper input validation within SQL Server’s processing mechanisms, leading to the potential disclosure of uninitialized memory contents.
Key Points:
1. Vulnerability Overview: CVE-2025-49719 is an information disclosure vulnerability stemming from inadequate input validation in SQL Server. Attackers can exploit this flaw to access uninitialized memory, potentially revealing confidential database information.
2. Affected Versions: The vulnerability impacts multiple versions of SQL Server, including 2016, 2017, 2019, and 2022. Microsoft has released security updates on July 8, 2025, to address this issue.
3. Severity and Exploitability: With a CVSS 3.1 base score of 7.5, this vulnerability is classified as Important. It is exploitable over the network with low complexity, requiring no privileges or user interaction, making it a significant concern for enterprise environments.
4. Remediation: Microsoft has provided comprehensive security updates for all supported SQL Server versions. Organizations are strongly advised to apply these patches immediately to mitigate the risk.
Technical Details:
The CVE-2025-49719 vulnerability is categorized under CWE-20: Improper Input Validation. This flaw allows attackers to exploit insufficient input validation routines, potentially accessing uninitialized memory regions that may contain sensitive database information, connection strings, or other confidential data structures.
The vulnerability’s attack vector is particularly concerning for enterprise environments. The CVSS vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N indicates network-based attacks with low complexity, requiring no privileges or user interaction. This configuration enables remote attackers to potentially extract sensitive information from SQL Server instances exposed to network access, making it a prime target for automated exploitation tools and reconnaissance activities.
The exploitation mechanism leverages network-based attack vectors that require no authentication credentials or user interaction, significantly lowering the barrier for successful attacks. Attackers can craft malicious network packets targeting SQL Server’s input validation routines, potentially triggering the disclosure of uninitialized memory contents. The vulnerability’s network accessibility means that any SQL Server instance reachable over TCP/IP connections could be vulnerable to information disclosure attacks.
The exploitability assessment indicates that while the vulnerability has been publicly disclosed, active exploitation remains Less Likely according to Microsoft’s analysis. However, the combination of network accessibility and no authentication requirements creates a substantial attack surface for threat actors. Organizations running SQL Server in cloud environments, particularly Windows Azure IaaS deployments, face additional exposure risks due to the broader network attack surface inherent in cloud infrastructure.
Risk Factors:
– Affected Products: Microsoft SQL Server 2016, 2017, 2019, 2022 (all supported versions; various GDR/CU builds)
– Impact: Information Disclosure
– Exploit Prerequisites: No authentication or user interaction required
– CVSS 3.1 Score: 7.5 (High)
Remediation Steps:
Microsoft has released comprehensive security updates addressing CVE-2025-49719 across all supported SQL Server versions. The remediation strategy involves applying version-specific updates, including both General Distribution Release (GDR) and Cumulative Update (CU) packages.
Critical updates include KB 5058721 for SQL Server 2022 CU19+GDR (version 16.0.4200.1), KB 5058722 for SQL Server 2019 CU32+GDR (version 15.0.4435.7), and KB 5058714 for SQL Server 2017 CU31+GDR (version 14.0.3495.9).
Organizations must prioritize immediate patch deployment, particularly for internet-facing SQL Server instances. Database administrators should implement network segmentation and access controls as additional protective measures while coordinating update deployment across enterprise environments.
Conclusion:
The discovery of CVE-2025-49719 underscores the critical importance of maintaining up-to-date security measures within enterprise environments. Organizations utilizing Microsoft SQL Server must act swiftly to apply the necessary patches and implement additional security controls to mitigate the risk posed by this vulnerability.
