CVE-2019-12271 in Centraleyezer
Summary
by MITRE
Sandline Centraleyezer (On Premises) allows unrestricted File Upload with a dangerous type, because the feature of adding ".jpg" to any uploaded filename is not enforced on the server side.
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Analysis
by VulDB Data Team • 02/23/2024
The vulnerability identified as CVE-2019-12271 affects Sandline Centraleyezer On Premises software, representing a critical security flaw in the file upload functionality that enables arbitrary code execution. This issue stems from insufficient server-side validation mechanisms that fail to properly enforce filename extensions, creating a pathway for malicious actors to upload potentially harmful files with deceptive naming conventions.
The technical flaw manifests in the application's handling of file uploads where the system relies on client-side checks rather than robust server-side validation. While the interface may appear to enforce the addition of .jpg extensions to uploaded files, this restriction is not implemented on the server side, allowing attackers to bypass these controls by renaming malicious files with legitimate extensions such as .jpg, .png, or other image formats. This weakness directly maps to CWE-434 which describes insecure file upload vulnerabilities where applications accept files without proper validation of their content or extension.
The operational impact of this vulnerability is severe as it provides attackers with the ability to upload malicious scripts or executables that can be executed within the application's environment. An attacker could upload a web shell with a .jpg extension, making it appear as a legitimate image file while actually containing malicious code that can be executed server-side. This creates a persistent backdoor for unauthorized access and can lead to complete system compromise, data exfiltration, and lateral movement within the network. The vulnerability aligns with ATT&CK technique T1190 which describes exploiting vulnerabilities in web applications to gain initial access and establish persistence.
Security implications extend beyond immediate exploitation as the flaw enables attackers to maintain long-term access to the compromised system. The unrestricted file upload capability can be leveraged to deploy additional malware, establish command and control channels, or perform further reconnaissance activities. Organizations using Sandline Centraleyezer On Premises are particularly vulnerable as this represents a server-side configuration issue that cannot be mitigated through client-side security measures alone. The vulnerability demonstrates poor defense-in-depth principles where multiple layers of security controls should have been implemented to prevent such dangerous file uploads from being processed.
Mitigation strategies should focus on implementing comprehensive server-side validation mechanisms that verify both file extensions and content types. Organizations must enforce strict file type restrictions, implement proper file validation routines, and conduct thorough content analysis of uploaded files rather than relying on extension-based checks alone. Additionally, the application should employ secure file storage practices, including proper file permissions, sanitization of uploaded files, and regular security auditing of file upload functionality. The remediation should address the root cause by ensuring that all file upload operations are validated server-side and that the system rejects any files that do not meet predetermined security criteria, regardless of their apparent extension or content type.