CVE-2021-38159: Progress MOVEit Transfer SQLi Vulnerability

CVE-2021-38159 Overview

CVE-2021-38159 is a critical SQL Injection vulnerability affecting Progress MOVEit Transfer, a widely-used managed file transfer solution deployed across enterprise environments. The vulnerability exists in the MOVEit Transfer web application, allowing unauthenticated remote attackers to gain unauthorized access to the database backend through specially crafted input strings sent to unique MOVEit Transfer transaction types.

The impact varies depending on the underlying database engine (MySQL, Microsoft SQL Server, or Azure SQL), but attackers may be able to infer information about database structure and contents, or execute SQL statements that alter or delete database elements without authentication.

Critical Impact

Unauthenticated remote attackers can compromise database confidentiality, integrity, and availability through SQL injection, potentially leading to full database compromise and data exfiltration.

Affected Products

• Progress MOVEit Transfer versions before 2021.0.4 (13.0.4)
• Progress MOVEit Transfer versions before 2020.1.6 (12.1.6)
• Progress MOVEit Transfer versions before 2020.0.7 (12.0.7)
• Progress MOVEit Transfer versions before 2019.2.4 (11.2.4)
• Progress MOVEit Transfer versions before 2019.1.7 (11.1.7)
• Progress MOVEit Transfer versions before 2019.0.8 (11.0.8)

Discovery Timeline

• August 7, 2021 - CVE-2021-38159 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2021-38159

Vulnerability Analysis

This SQL Injection vulnerability (CWE-89) allows unauthenticated attackers to manipulate database queries through the MOVEit Transfer web application. The flaw stems from improper neutralization of special elements used in SQL commands, enabling attackers to inject malicious SQL code via crafted strings targeting unique MOVEit Transfer transaction types.

The attack is particularly dangerous because it requires no authentication and can be executed remotely over the network. Since MOVEit Transfer is commonly used for sensitive file transfers in enterprise environments, successful exploitation could expose confidential business data, personally identifiable information (PII), or enable attackers to establish persistence within the target environment.

Root Cause

The vulnerability originates from insufficient input validation and improper sanitization of user-supplied data within the MOVEit Transfer web application. When processing certain transaction types, the application fails to properly escape or parameterize user input before incorporating it into SQL queries. This allows attackers to break out of the intended query context and inject arbitrary SQL commands.

The lack of prepared statements or parameterized queries for these specific transaction handlers creates a direct path for SQL injection attacks. The vulnerability affects multiple database backends (MySQL, Microsoft SQL Server, and Azure SQL), indicating the injection point occurs at the application layer before database-specific query construction.

Attack Vector

The attack vector is network-based and requires no authentication or user interaction. An attacker can exploit this vulnerability by:

1. Identifying a vulnerable MOVEit Transfer instance exposed to the network
2. Crafting malicious SQL injection payloads targeting unique MOVEit Transfer transaction types
3. Sending the crafted strings to the web application endpoints
4. Extracting database information through inference techniques (blind SQL injection) or direct data retrieval
5. Potentially modifying or deleting database elements to disrupt operations or cover tracks

The specific exploitation technique depends on the underlying database engine, with each platform offering different capabilities for data extraction and command execution.

Detection Methods for CVE-2021-38159

Indicators of Compromise

• Anomalous HTTP requests to MOVEit Transfer endpoints containing SQL syntax characters (e.g., single quotes, UNION statements, OR 1=1 patterns)
• Unexpected database queries or errors in database server logs
• Unusual data access patterns or bulk data retrieval from MOVEit Transfer database
• Web application firewall (WAF) alerts for SQL injection attempts targeting MOVEit Transfer URLs
• Database performance degradation or timeout errors coinciding with suspicious web traffic

Detection Strategies

• Deploy web application firewall (WAF) rules specifically targeting SQL injection patterns in MOVEit Transfer transaction parameters
• Enable detailed logging on MOVEit Transfer web servers and correlate with database query logs
• Monitor for unusual outbound data transfers that could indicate data exfiltration following successful exploitation
• Implement database activity monitoring to detect anomalous query patterns or privilege escalation attempts

Monitoring Recommendations

• Enable verbose logging on MOVEit Transfer and forward logs to a SIEM for centralized analysis
• Configure alerting for authentication failures combined with database errors
• Monitor network traffic for large data transfers from database servers
• Regularly audit database user privileges and review access patterns for anomalies

How to Mitigate CVE-2021-38159

Immediate Actions Required

• Upgrade Progress MOVEit Transfer to a patched version immediately
• If immediate patching is not possible, restrict network access to MOVEit Transfer to trusted IP addresses only
• Enable web application firewall rules to block common SQL injection patterns
• Review database and application logs for signs of prior exploitation
• Consider taking vulnerable instances offline until patching is complete

Patch Information

Progress has released security patches addressing this vulnerability. Organizations should upgrade to one of the following fixed versions:

For detailed patching instructions, refer to the Progress MOVEit Vulnerability Advisory.

Workarounds

• Implement network segmentation to limit exposure of MOVEit Transfer instances to untrusted networks
• Deploy a web application firewall (WAF) with SQL injection detection capabilities in front of MOVEit Transfer
• Apply strict IP whitelisting to limit access to known, trusted sources
• Enable database connection encryption and implement least-privilege database accounts for the MOVEit Transfer application
• Conduct a security audit of database permissions to ensure the application account has minimal required privileges