CVE-2021-28271 in 701Server
Summary
by MITRE • 04/27/2021
Soyal Technologies SOYAL 701Server 9.0.1 suffers from an elevation of privileges vulnerability which can be used by an authenticated user to change the executable file with a binary choice. The vulnerability is due to improper permissions with the 'F' flag (Full) for 'Everyone'and 'Authenticated Users' group.
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Analysis
by VulDB Data Team • 05/02/2021
The CVE-2021-28271 vulnerability affects Soyal Technologies SOYAL 701Server version 9.0.1, representing a critical privilege escalation flaw that undermines the security posture of the affected system. This vulnerability resides within the file permission configuration of the server software, specifically manifesting through improper access controls that allow authenticated users to manipulate executable files. The issue stems from the configuration where the 'F' flag (Full Control) is granted to both 'Everyone' and 'Authenticated Users' groups, creating an exploitable path for unauthorized modification of critical system components.
The technical implementation of this vulnerability exploits weak permission models within the server's file system access controls. When the 'F' flag is improperly assigned to broad user groups, it grants full control permissions that include the ability to read, write, modify, and delete files. An authenticated user can leverage this misconfiguration to replace legitimate executable files with malicious binaries, effectively gaining elevated privileges beyond their original authentication scope. This flaw operates at the operating system level where file permissions are not properly enforced, creating a path for privilege escalation that bypasses normal security boundaries.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass potential system compromise and persistent access. An attacker with authenticated access can replace critical executables with backdoor binaries, potentially maintaining access even after initial authentication expires. The vulnerability affects the integrity and availability of the server's core functionality, as legitimate executable files can be replaced without proper authorization mechanisms. This creates a persistent threat vector where the attacker can execute arbitrary code with elevated privileges, potentially leading to complete system compromise and data exfiltration.
Mitigation strategies for CVE-2021-28271 must focus on immediate permission remediation and long-term access control hardening. Organizations should immediately review and correct the file permissions for all executable components, removing the 'F' flag from 'Everyone' and 'Authenticated Users' groups while implementing principle of least privilege access controls. The remediation process should involve implementing proper access control lists that restrict file modifications to authorized administrators only. Additionally, implementing file integrity monitoring solutions and regular permission audits can help detect and prevent similar misconfigurations. This vulnerability aligns with CWE-276, which addresses incorrect permission assignment, and maps to ATT&CK technique T1068, privilege escalation through local exploitation, highlighting the need for comprehensive system hardening and access control management practices.