CVE-2019-7725 in NukeViet
Summary
by MITRE • 12/31/2020
includes/core/is_user.php in NukeViet before 4.3.04 deserializes the untrusted nvloginhash cookie (i.e., the code relies on PHP's serialization format when JSON can be used to eliminate the risk).
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Analysis
by VulDB Data Team • 12/31/2020
The vulnerability identified in NukeViet versions prior to 4.3.04 resides within the includes/core/is_user.php file where the system deserializes an untrusted nvloginhash cookie value without proper validation or sanitization. This represents a critical security flaw that allows attackers to potentially execute arbitrary code or manipulate authentication mechanisms through maliciously crafted cookie data. The flaw stems from the application's reliance on PHP's native serialization format rather than safer alternatives like JSON, which eliminates the risk of object injection attacks that are common in PHP deserialization vulnerabilities. This vulnerability directly maps to CWE-502 which describes "Deserialization of Untrusted Data" and represents a well-documented attack vector where malicious input can be used to execute code or manipulate application behavior. The operational impact of this vulnerability is significant as it could allow unauthorized users to bypass authentication mechanisms, escalate privileges, or potentially gain full control over the affected system. Attackers could craft malicious nvloginhash cookie values that, when processed by the vulnerable deserialization code, would execute arbitrary PHP code on the server. This type of vulnerability aligns with ATT&CK technique T1210 which covers "Exploitation of Remote Services" and specifically addresses credential access through authentication bypass mechanisms. The issue demonstrates poor input validation practices and highlights the importance of implementing secure coding standards that avoid dangerous deserialization patterns. The use of PHP's unserialize() function without proper sanitization creates an attack surface where malicious actors can inject serialized objects that execute unintended code during the deserialization process. This vulnerability type is particularly dangerous because it can be exploited remotely without requiring authentication, making it an attractive target for automated attacks. The security implications extend beyond simple authentication bypass to potentially allow full system compromise through code execution. Organizations using affected versions of NukeViet should immediately implement mitigations including upgrading to version 4.3.04 or later, implementing proper input validation for cookie data, and considering alternative serialization methods that do not pose the same risks as PHP's native deserialization. Additionally, network segmentation and monitoring for suspicious cookie values can help detect potential exploitation attempts. The vulnerability underscores the critical need for secure coding practices and the importance of avoiding dangerous functions like unserialize() when processing untrusted data from user inputs or cookies. This flaw represents a fundamental security weakness that could be leveraged by attackers to establish persistent access to the affected systems.