CVE-2023-39109 in rconfig
Summary
by MITRE • 08/01/2023
rconfig v3.9.4 was discovered to contain a Server-Side Request Forgery (SSRF) via the path_a parameter in the doDiff Function of /classes/compareClass.php. This vulnerability allows authenticated attackers to make arbitrary requests via injection of crafted URLs.
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Analysis
by VulDB Data Team • 08/24/2023
The vulnerability identified as CVE-2023-39109 affects rconfig version 3.9.4 and represents a critical server-side request forgery flaw within the application's comparison functionality. This issue resides in the doDiff function located within the /classes/compareClass.php file where the path_a parameter fails to properly validate or sanitize user input before processing. The vulnerability enables authenticated attackers to inject malicious URLs that the application will subsequently attempt to access on their behalf, effectively creating a pathway for unauthorized network reconnaissance and potential data exfiltration.
The technical implementation of this SSRF vulnerability stems from inadequate input validation mechanisms within the comparison class functionality. When an authenticated user submits a request containing a crafted path_a parameter, the application processes this input without sufficient sanitization measures that would normally prevent malicious URL schemes or internal network addresses from being executed. This flaw directly maps to CWE-918, which specifically addresses server-side request forgery vulnerabilities where applications fail to properly validate external resource requests. The vulnerability operates at the application layer and can be exploited through the web interface, making it particularly dangerous as it requires only authentication to the system rather than elevated privileges.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables attackers to perform various malicious activities including internal network scanning, service enumeration, and potential data exfiltration from internal systems that the application server can reach. An attacker could leverage this vulnerability to probe internal network services, access internal APIs, or even attempt to reach sensitive systems that would normally be protected by network segmentation. The authenticated nature of the exploit means that attackers do not require external network access to perform these attacks, as they can utilize legitimate user sessions to make requests that bypass normal network security controls. This vulnerability aligns with ATT&CK technique T1566.002 which describes server-side request forgery as a method for bypassing network security controls and accessing internal resources.
Mitigation strategies for this vulnerability should focus on implementing robust input validation and sanitization mechanisms within the affected application components. The primary fix involves modifying the doDiff function in compareClass.php to properly validate and sanitize all input parameters, particularly those related to URL schemes and network addresses. Implementing a whitelist approach that only allows specific, trusted URL schemes and domains would effectively prevent malicious URL injection attempts. Additionally, organizations should consider implementing network segmentation and firewall rules to limit the application server's access to internal network resources, thereby reducing the potential impact of successful exploitation. Regular security assessments and input validation reviews should be conducted to identify similar vulnerabilities in other application components, as this type of flaw often indicates broader issues with data sanitization practices within the application codebase. The vulnerability serves as a reminder of the critical importance of validating all external input and implementing proper access controls to prevent unauthorized resource access through legitimate application functionality.