CVE-2025-49758 Overview
CVE-2025-49758 is a SQL injection vulnerability in Microsoft SQL Server that allows an authenticated attacker to elevate privileges over a network. The flaw stems from improper neutralization of special elements used in SQL commands, enabling attackers to manipulate query execution. An attacker holding low-privilege credentials can leverage the issue to gain higher-level rights on the database server.
Critical Impact
Successful exploitation grants elevated privileges on SQL Server instances, exposing confidentiality, integrity, and availability of database assets to compromise.
Affected Products
- Microsoft SQL Server 2016 (x64)
- Microsoft SQL Server 2017 (x64)
- Microsoft SQL Server 2019 (x64)
- Microsoft SQL Server 2022 (x64)
Discovery Timeline
- 2025-08-12 - CVE-2025-49758 published to NVD
- 2025-08-12 - Microsoft publishes security update for CVE-2025-49758
- 2025-08-14 - Last updated in NVD database
Technical Details for CVE-2025-49758
Vulnerability Analysis
The vulnerability is classified under [CWE-269] Improper Privilege Management and originates from SQL injection in Microsoft SQL Server. The server fails to neutralize special elements within SQL statements before they reach the query parser. An attacker with valid database credentials can inject crafted SQL fragments through vulnerable input paths.
Once injected, the malicious statements execute under a security context that exceeds the attacker's assigned privileges. The result is vertical privilege escalation within the database engine. Exploitation requires network access and authentication, but no user interaction. The EPSS score of 0.7% places this issue in the 72nd percentile for predicted exploitation activity.
Root Cause
The root cause is missing or insufficient input sanitization in SQL Server code paths that build dynamic queries. When user-controlled data is concatenated into SQL statements without parameterization, attackers can break out of expected syntax. This allows execution of arbitrary SQL under a higher-privileged context.
Attack Vector
The attack vector is network-based and requires low-privilege authenticated access to the SQL Server instance. An attacker submits a crafted query or input through an exposed interface that reaches the vulnerable code path. The injected payload alters the query logic to escalate the session's effective privileges. No social engineering or victim interaction is required for the attack chain.
For implementation specifics, refer to the Microsoft Security Update CVE-2025-49758.
Detection Methods for CVE-2025-49758
Indicators of Compromise
- Unexpected execution of T-SQL statements containing union, stacked queries, or comment sequences from low-privilege accounts.
- New logins, role memberships, or permission grants created outside change-control windows.
- Anomalous activity from sysadmin or db_owner roles linked to accounts that historically held limited rights.
- SQL Server error log entries showing syntax errors followed by successful privileged operations from the same session.
Detection Strategies
- Enable SQL Server Audit and capture SCHEMA_OBJECT_ACCESS_GROUP and SERVER_PERMISSION_CHANGE_GROUP events for review.
- Hunt for query patterns containing injection markers such as ';--, OR 1=1, or EXEC( originating from application service accounts.
- Baseline normal query shapes per account and alert on deviations in privilege-sensitive operations.
- Correlate authentication events with subsequent role or permission changes to surface escalation chains.
Monitoring Recommendations
- Forward SQL Server audit logs and Extended Events traces to a centralized analytics platform for correlation.
- Monitor for privilege grants involving sysadmin, securityadmin, or db_owner roles in real time.
- Track failed login bursts followed by successful authentication from the same source as a precursor to credentialed exploitation.
How to Mitigate CVE-2025-49758
Immediate Actions Required
- Apply the Microsoft security update referenced in the MSRC advisory for CVE-2025-49758 to all affected SQL Server 2016, 2017, 2019, and 2022 instances.
- Inventory SQL Server deployments and prioritize patching internet-reachable and high-value databases first.
- Rotate credentials for service accounts and application identities that connect to SQL Server with elevated rights.
- Review recent audit logs for indicators of unauthorized privilege changes prior to patch deployment.
Patch Information
Microsoft released updates addressing CVE-2025-49758 on 2025-08-12. The advisory and downloadable patches are available from the Microsoft Security Update Guide. Administrators should follow standard cumulative update procedures and verify build numbers after deployment.
Workarounds
- Restrict network access to SQL Server using firewalls and network segmentation, limiting connections to known application hosts.
- Enforce the principle of least privilege on all database logins and remove unnecessary role memberships.
- Require parameterized queries and stored procedures in application code to reduce exploitable injection paths.
- Enable SQL Server Audit with privilege-change events forwarded to centralized monitoring until patches are applied.
# Verify SQL Server build number after patching
sqlcmd -S <server> -Q "SELECT SERVERPROPERTY('ProductVersion') AS Version, SERVERPROPERTY('ProductLevel') AS Level;"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
