CVE-2020-1455 Overview
CVE-2020-1455 is a denial of service vulnerability in Microsoft SQL Server Management Studio (SSMS). The flaw stems from improper file handling within SSMS. An authenticated local attacker with existing code execution on the target system can exploit the issue to disrupt SSMS availability. Microsoft addressed the vulnerability by correcting how SSMS processes files. The issue affects availability only, with no impact to confidentiality or integrity.
Critical Impact
An authenticated local attacker can trigger a denial of service condition in Microsoft SQL Server Management Studio, disrupting database administration workflows on affected hosts.
Affected Products
- Microsoft SQL Server Management Studio (SSMS)
- Database administrator workstations running vulnerable SSMS builds
- Systems where SSMS is used to manage Microsoft SQL Server instances
Discovery Timeline
- 2020-08-17 - CVE-2020-1455 published to NVD
- 2026-02-23 - Last updated in NVD database
Technical Details for CVE-2020-1455
Vulnerability Analysis
The vulnerability resides in how Microsoft SQL Server Management Studio parses or handles files presented to the application. Improper file handling causes the application to consume excessive resources or terminate, producing a denial of service condition. The flaw requires local access and low privileges. No user interaction is needed beyond the attacker's own execution on the host. The attack scope is unchanged, and the impact is limited to availability. Confidentiality and integrity of database data are not affected directly by this issue. NVD classifies the weakness as NVD-CWE-noinfo because Microsoft did not publish a specific CWE category for the underlying defect.
Root Cause
The root cause is improper file handling within SSMS. Microsoft's advisory states that the security update ensures SSMS properly handles files. Public technical details on the specific parser or component are not available in the advisory.
Attack Vector
Exploitation requires local execution on the victim system. An attacker first obtains code execution as any user, then delivers a malformed file to SSMS for processing. When SSMS opens or processes the file, the application enters a state that disrupts service. The vulnerability is not network-exploitable and is not listed in the CISA Known Exploited Vulnerabilities catalog.
No verified public proof-of-concept code is available for this issue. Refer to the Microsoft Security Advisory CVE-2020-1455 for vendor-provided technical guidance.
Detection Methods for CVE-2020-1455
Indicators of Compromise
- Repeated unexpected termination or hang states of the Ssms.exe process on database administrator workstations.
- Windows Application event log entries showing SSMS crashes or faulting modules associated with file parsing.
- Anomalous file drops in user-writable directories followed by SSMS being invoked to open those files.
Detection Strategies
- Monitor process telemetry for Ssms.exe crash and restart loops correlated with file-open events.
- Correlate local logon sessions with file creation events and subsequent SSMS file-open activity to identify abuse patterns.
- Track installed SSMS versions across the estate and flag hosts running builds prior to the Microsoft August 2020 security update.
Monitoring Recommendations
- Forward Windows Application and Security event logs from administrator workstations to a centralized analytics platform for crash pattern analysis.
- Alert on local privilege use or new process creation under accounts that should not be running SSMS.
- Audit which users interactively launch SSMS and from which file paths, focusing on temp and download directories.
How to Mitigate CVE-2020-1455
Immediate Actions Required
- Apply the Microsoft security update for SQL Server Management Studio referenced in the MSRC advisory.
- Inventory all workstations and jump hosts running SSMS and identify versions predating the August 2020 update.
- Restrict interactive logon on database administration hosts to authorized personnel only.
Patch Information
Microsoft released a security update that corrects how SSMS handles files. Administrators should install the latest available SSMS release from Microsoft. Consult the Microsoft Security Advisory CVE-2020-1455 for affected build ranges and download links.
Workarounds
- Do not open SSMS project files, scripts, or database files from untrusted or user-writable locations.
- Enforce least privilege so non-administrative users cannot execute code on hosts where SSMS is installed.
- Use application allowlisting to limit which files SSMS can open on shared administration workstations.
# Configuration example: query installed SSMS version on Windows hosts via PowerShell
Get-ItemProperty 'HKLM:\Software\Microsoft\Microsoft SQL Server Management Studio\*' |
Select-Object DisplayName, DisplayVersion, InstallLocation
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
