CVE-2020-9352 in SmartClient
Summary
by MITRE
An issue was discovered in SmartClient 12.0. Unauthenticated exploitation of blind XXE can occur in the downloadWSDL feature by sending a POST request to /tools/developerConsoleOperations.jsp with a valid payload in the _transaction parameter.
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Analysis
by VulDB Data Team • 06/27/2024
The vulnerability identified as CVE-2020-9352 represents a critical blind xml external entity injection flaw within SmartClient 12.0 software. This issue resides in the downloadWSDL feature which operates through a POST request endpoint at /tools/developerConsoleOperations.jsp. The vulnerability allows unauthenticated attackers to exploit the system by manipulating the _transaction parameter to inject malicious xml entities that can reference external resources. This blind XXE vulnerability stems from insufficient input validation and sanitization of user-supplied data within the web application's processing pipeline. The flaw enables attackers to perform various malicious activities including data exfiltration, internal network reconnaissance, and potential server-side request forgery attacks.
The technical exploitation of this vulnerability occurs through the manipulation of the _transaction parameter in the POST request to the developerConsoleOperations.jsp endpoint. When the application processes this parameter without proper validation, it inadvertently parses xml content that may contain external entity references. These references can point to external servers or internal resources, allowing attackers to harvest sensitive data or perform unauthorized operations. The blind nature of this vulnerability means that attackers cannot directly observe the response from their injected entities, making detection more challenging but not impossible through indirect methods such as out-of-band interactions or timing attacks. This particular flaw aligns with CWE-611 which specifically addresses improper restriction of XML external entity reference and falls under the broader category of xml injection vulnerabilities.
The operational impact of CVE-2020-9352 extends beyond simple data theft to encompass potential system compromise and unauthorized access to internal resources. Attackers can leverage this vulnerability to enumerate internal network services, access sensitive files on the server, or perform server-side request forgery attacks against other internal systems. The unauthenticated nature of the exploit significantly increases the risk as any user with access to the application can potentially exploit this flaw. This vulnerability particularly affects organizations that rely on SmartClient for their web applications and development environments, as it provides a direct path for attackers to escalate privileges and gain deeper access to the underlying infrastructure. The vulnerability also poses risks to data confidentiality and integrity, as attackers can potentially modify or extract sensitive information through the blind XXE mechanism.
Organizations affected by CVE-2020-9352 should implement immediate mitigations including input validation and sanitization of all user-supplied data, particularly xml content. The most effective approach involves disabling external entity processing in xml parsers and implementing proper xml schema validation to prevent malicious entities from being processed. Additionally, network segmentation and firewall rules should be configured to restrict access to the vulnerable endpoint and limit the attack surface. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other applications. The mitigation strategies align with established security frameworks and practices including the principle of least privilege, input validation, and proper xml processing configurations as recommended by industry standards such as those outlined in the owasp top ten and nist cybersecurity framework. Organizations should also monitor for any out-of-band network connections that may indicate exploitation attempts and maintain detailed logging of all requests to the vulnerable endpoint for forensic analysis.