CVE-2018-20061 in ERPNext
Summary
by MITRE
A SQL injection issue was discovered in ERPNext 10.x and 11.x through 11.0.3-beta.29. This attack is only available to a logged-in user; however, many ERPNext sites allow account creation via the web. No special privileges are needed to conduct the attack. By calling a JavaScript function that calls a server-side Python function with carefully chosen arguments, a SQL attack can be carried out which allows SQL queries to be constructed to return any columns from any tables in the database. This is related to /api/resource/Item?fields= URIs, frappe.get_list, and frappe.call.
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Analysis
by VulDB Data Team • 06/18/2023
CVE-2018-20061 represents a critical SQL injection vulnerability affecting ERPNext versions 10.x and 11.x up to 11.0.3-beta.29. This vulnerability resides within the application's handling of API requests, specifically targeting the /api/resource/Item?fields= endpoint which utilizes frappe.get_list and frappe.call functions. The flaw stems from insufficient input validation and sanitization when processing user-supplied parameters, allowing maliciously crafted requests to manipulate the underlying SQL query execution. The vulnerability is categorized under CWE-89 SQL Injection, which is a well-established weakness in web applications where user input is directly incorporated into SQL commands without proper escaping or parameterization. Attackers can exploit this vulnerability by leveraging the JavaScript functions that interface with server-side Python code, creating a path for unauthorized database access through carefully constructed arguments that bypass normal input validation mechanisms. The attack requires only a valid user account to execute successfully, which is particularly concerning given that many ERPNext installations allow public registration, effectively reducing the barrier to entry for potential attackers.
The operational impact of this vulnerability extends beyond simple data theft, as it provides attackers with the capability to extract any columns from any tables within the database through crafted SQL queries. This level of access enables comprehensive data exfiltration, privilege escalation, and potential system compromise. The vulnerability specifically targets the Item resource API endpoint, which is fundamental to ERPNext's functionality, making it a high-value target for attackers seeking to disrupt business operations or gain access to sensitive financial and operational data. The exploitation process involves calling JavaScript functions that subsequently invoke server-side Python functions with manipulated parameters, creating a chain of execution that ultimately leads to SQL injection. This attack vector is particularly dangerous because it requires no elevated privileges and can be executed by any authenticated user, potentially allowing attackers to escalate their access rights or gain unauthorized administrative capabilities within the system. The vulnerability demonstrates a failure in the principle of least privilege and proper input validation, as the application does not adequately sanitize user inputs before incorporating them into database queries.
Mitigation strategies for CVE-2018-20061 should focus on immediate patching of affected ERPNext versions, with the implementation of proper parameterized queries and input validation mechanisms. Organizations should enforce strict access controls and monitor user activities for suspicious API calls, particularly those involving the Item resource endpoint. The solution involves implementing proper database query parameterization to prevent user input from being interpreted as SQL commands, which aligns with ATT&CK technique T1071.004 Application Layer Protocol: Web Protocols. Additionally, organizations should consider implementing web application firewalls and input sanitization measures to detect and block malicious requests before they reach the vulnerable code paths. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in the application's API endpoints, with particular attention to how user inputs are processed in server-side functions. The vulnerability also highlights the importance of secure coding practices and proper input validation, as outlined in OWASP Top Ten categories and NIST SP 800-53 security controls, emphasizing the need for comprehensive security measures throughout the software development lifecycle rather than reactive patching approaches.