CVE-2018-6592 in Stealth Windows
Summary
by MITRE
Unisys Stealth Windows endpoints before 3.3.016.1 allow local users to gain access to Stealth-enabled devices by leveraging improper cleanup of memory used for negotiation key storage.
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Analysis
by VulDB Data Team • 01/07/2020
The vulnerability identified as CVE-2018-6592 affects Unisys Stealth Windows endpoints prior to version 3.3.016.1, representing a critical security flaw that undermines the integrity of encrypted communications. This issue stems from inadequate memory management practices during the key negotiation process, creating persistent security weaknesses that can be exploited by local attackers. The vulnerability specifically targets the memory cleanup mechanisms responsible for handling negotiation keys, which are essential components in establishing secure communication channels between endpoints.
The technical flaw manifests through improper memory deallocation processes where cryptographic keys used during the negotiation phase are not adequately cleared from memory space after their intended use. This memory leakage creates a persistent exposure that allows unauthorized local users to potentially access or reconstruct sensitive cryptographic material. The vulnerability operates at the system level where memory management routines fail to properly overwrite or securely dispose of key material, leaving residual data accessible to processes running with appropriate privileges. This type of flaw falls under the broader category of memory corruption vulnerabilities and can be classified as a CWE-127 weakness related to improper cleanup of memory.
From an operational standpoint, this vulnerability significantly compromises the security posture of systems relying on Unisys Stealth protection mechanisms. Local users who can execute code on the target system gain the ability to access stealth-enabled devices without proper authentication, effectively bypassing the encryption and security controls that the Stealth technology is designed to enforce. The impact extends beyond simple privilege escalation as it potentially enables attackers to decrypt communications, access protected data, and compromise the confidentiality assurances provided by the encryption framework. This vulnerability particularly affects enterprise environments where multiple users may have local access to systems running Unisys Stealth, creating a wide attack surface.
The exploitability of this vulnerability aligns with ATT&CK technique T1059.001 for command and script interpreter execution, as local users can leverage the compromised memory state to gain elevated access. Security professionals should consider implementing immediate patch management procedures to address this vulnerability, as the remediation involves updating to Unisys Stealth version 3.3.016.1 or later. Organizations should also conduct thorough vulnerability assessments to identify systems running affected versions and implement monitoring controls to detect potential exploitation attempts. The memory cleanup mechanism should be reviewed and hardened to ensure proper key material disposal, and system administrators should consider implementing additional access controls to limit local user privileges where possible. This vulnerability demonstrates the critical importance of secure memory management practices in cryptographic systems and highlights the need for comprehensive security testing of encryption implementations.