CVE-2017-6527 in dnaLIMS
Summary
by MITRE
An issue was discovered in dnaTools dnaLIMS 4-2015s13. dnaLIMS is vulnerable to a NUL-terminated directory traversal attack allowing an unauthenticated attacker to access system files readable by the web server user (by using the viewAppletFsa.cgi seqID parameter).
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 06/30/2024
The vulnerability identified as CVE-2017-6527 affects dnaTools dnaLIMS version 4-2015s13, representing a critical directory traversal flaw that exposes sensitive system resources to unauthenticated attackers. This issue manifests through the viewAppletFsa.cgi script's seqID parameter, which fails to properly validate user input before processing file system requests. The vulnerability stems from insufficient input sanitization mechanisms that allow malicious actors to manipulate the seqID parameter with specially crafted directory traversal sequences, effectively bypassing normal access controls and gaining unauthorized access to files that the web server process is authorized to read. The flaw operates by exploiting the web server's file resolution behavior when processing NUL-terminated strings, which can cause the application to interpret user-supplied paths differently than intended, leading to unintended file system access patterns.
The technical exploitation of this vulnerability follows a classic directory traversal attack pattern where an attacker crafts malicious input to navigate outside the intended directory boundaries. When the seqID parameter contains directory traversal sequences such as "../" or similar constructs, the vulnerable application processes these without adequate validation, allowing access to files that should remain protected. The NUL termination aspect of the attack is particularly significant as it can manipulate string processing functions within the web application, potentially causing buffer overflows or altering string parsing behavior in ways that bypass traditional input validation checks. This vulnerability directly maps to CWE-22, which defines improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The attack vector specifically aligns with ATT&CK technique T1083, which covers discovering files and directories, and T1059, which encompasses command and scripting interpreter usage, as attackers may leverage this vulnerability to execute commands or extract sensitive information from the system.
The operational impact of CVE-2017-6527 extends beyond simple information disclosure, as it provides attackers with potential access to sensitive configuration files, database credentials, application source code, and other system resources that the web server user can access. This exposure could lead to further compromise of the system through credential theft, privilege escalation opportunities, or the discovery of additional vulnerabilities within the application or underlying infrastructure. The unauthenticated nature of the attack means that any external party can exploit this vulnerability without requiring valid credentials, making it particularly dangerous in environments where the application is exposed to untrusted networks. Organizations using dnaLIMS 4-2015s13 are at significant risk of data breaches, regulatory compliance violations, and potential system compromise, especially if the web server has elevated privileges or access to sensitive data repositories. The vulnerability essentially undermines the application's security model by allowing arbitrary file access through a single parameter manipulation, creating a substantial attack surface that could be leveraged for more sophisticated exploitation techniques.
Mitigation strategies for this vulnerability should focus on immediate input validation and sanitization measures, including implementing strict parameter validation for the seqID field in viewAppletFsa.cgi and ensuring that all user-supplied input is properly escaped or filtered before processing. The application should enforce a whitelist approach for acceptable file paths and reject any input containing directory traversal sequences or special characters that could manipulate the file system resolution process. System administrators should also consider implementing web application firewalls to detect and block suspicious directory traversal patterns, while regular security assessments should be conducted to identify similar vulnerabilities in other applications within the infrastructure. Additionally, the affected dnaLIMS version should be upgraded to a patched release that addresses this specific vulnerability, as the vendor has likely provided security updates to resolve the input validation flaws. Organizations should also implement principle of least privilege for web server processes, ensuring that the web server user has minimal necessary permissions to reduce the potential impact of successful exploitation attempts. Regular security monitoring and log analysis should be implemented to detect unusual file access patterns that might indicate exploitation attempts against this or similar vulnerabilities.