CVE-2016-5374 in Data ONTAP
Summary
by MITRE
NetApp Data ONTAP 9.0 and 9.1 before 9.1P1 allows remote authenticated users that own SMB-hosted data to bypass intended sharing restrictions by leveraging improper handling of the owner_rights ACL entry.
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Analysis
by VulDB Data Team • 09/03/2020
The vulnerability identified as CVE-2016-5374 affects NetApp Data ONTAP versions 9.0 and 9.1 before 9.1P1, representing a critical access control flaw that undermines the security of SMB file sharing implementations. This vulnerability specifically targets the handling of owner_rights ACL entries within the SMB protocol implementation, creating a pathway for authenticated attackers who already possess legitimate access to SMB-hosted data to circumvent intended sharing restrictions. The flaw exists in the privilege escalation mechanism that governs how file permissions are enforced in SMB environments, allowing attackers to gain unauthorized access to resources they should not be able to access based on their assigned permissions.
The technical root cause of this vulnerability lies in the improper processing of owner_rights ACL entries within the NetApp Data ONTAP SMB implementation. When a user with legitimate access to SMB-hosted data attempts to access files or directories, the system fails to properly validate the ownership rights associated with these ACL entries. This misconfiguration allows malicious actors to exploit the system's permission model by manipulating the owner_rights attributes, effectively bypassing the intended access controls that should restrict file access based on user identity and group membership. The vulnerability manifests when the system processes ACL entries without adequate validation of the owner rights, creating a gap in the access control enforcement mechanism that can be leveraged by authenticated users.
From an operational impact perspective, this vulnerability poses significant risks to organizations relying on NetApp Data ONTAP for their SMB file sharing infrastructure. An authenticated attacker who already has access to SMB-hosted data can exploit this flaw to gain access to additional files and directories that should be restricted to other users or groups. This could lead to unauthorized data access, potential data exfiltration, and the compromise of sensitive information within the organization's file sharing environment. The impact extends beyond simple unauthorized access, as this vulnerability could enable attackers to escalate their privileges within the SMB environment and potentially move laterally within the network infrastructure.
The vulnerability aligns with CWE-284, which addresses improper access control issues in software implementations, and represents a classic example of how ACL handling flaws can create security loopholes. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and can be leveraged as part of lateral movement strategies within compromised environments. Organizations using NetApp Data ONTAP versions 9.0 and 9.1 before 9.1P1 should implement immediate mitigations including applying the vendor-provided security patches, reviewing existing SMB access controls, and monitoring for unauthorized access attempts. Network segmentation and least privilege access principles should be reinforced to minimize the potential impact of such vulnerabilities. The recommended solution involves upgrading to NetApp Data ONTAP 9.1P1 or later versions where the ACL handling for owner_rights entries has been properly addressed to prevent unauthorized access bypass scenarios.