CVE-2019-16896 in Ultimate Security
Summary
by MITRE
In K7 Ultimate Security 16.0.0117, the module K7BKCExt.dll (aka the backup module) improperly validates the administrative privileges of the user, allowing an arbitrary file write via a symbolic link attack with file restoration functionality.
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Analysis
by VulDB Data Team • 03/18/2024
The vulnerability identified as CVE-2019-16896 resides within K7 Ultimate Security version 16.0.0117, specifically within the K7BKCExt.dll module which serves as the backup component of the security suite. This flaw represents a critical privilege escalation vulnerability that stems from inadequate validation of administrative rights during file restoration operations. The issue manifests when the backup module fails to properly verify whether the executing user possesses sufficient privileges before performing file operations, creating an exploitable condition that can be leveraged by malicious actors.
The technical implementation of this vulnerability involves a symbolic link attack vector that exploits the file restoration functionality of the backup module. When the K7BKCExt.dll component processes file restoration requests, it does not adequately validate the administrative status of the user context, allowing a non-administrative user to create symbolic links that point to protected system files or directories. This misconfiguration enables an attacker to manipulate the restoration process such that files are written to unintended locations, effectively bypassing normal file system permissions and access controls.
The operational impact of CVE-2019-16896 extends beyond simple privilege escalation to encompass potential system compromise and data integrity violations. An attacker who successfully exploits this vulnerability can write arbitrary files to critical system locations, potentially installing malicious software, modifying system binaries, or corrupting essential files. The vulnerability aligns with CWE-276, which addresses improper privileges for critical operations, and represents a classic example of insufficient privilege checking in security-sensitive code paths. This weakness creates opportunities for persistent threats to establish footholds within compromised systems.
From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and can be leveraged for initial access or lateral movement within compromised environments. The exploitation requires minimal user interaction and can be automated, making it particularly dangerous in enterprise environments where security software is widely deployed. Organizations running K7 Ultimate Security version 16.0.0117 are at risk of unauthorized file modifications, system instability, and potential complete system compromise. The vulnerability demonstrates the importance of proper privilege validation in security software components, particularly those with elevated system access requirements.
Mitigation strategies for CVE-2019-16896 should prioritize immediate patching of the K7 Ultimate Security software to version 16.0.0118 or later, which contains the necessary fixes for the privilege validation issue. System administrators should also implement additional monitoring for suspicious file operations and symbolic link creation within backup and restoration processes. Network segmentation and privilege minimization practices can help limit the potential impact if exploitation occurs, while regular security assessments should verify that security software components properly validate administrative privileges before executing sensitive operations. The vulnerability underscores the critical need for security vendors to implement robust privilege validation mechanisms in all system-level components.