CVE-2017-17482 in OpenVMS
Summary
by MITRE
An issue was discovered in OpenVMS through V8.4-2L2 on Alpha and through V8.4-2L1 on IA64, and VAX/VMS 4.0 and later. A malformed DCL command table may result in a buffer overflow allowing a local privilege escalation when a non-privileged account enters a crafted command line. This bug is exploitable on VAX and Alpha and may cause a process crash on IA64. Software was affected regardless of whether it was directly shipped by VMS Software, Inc. (VSI), HPE, HP, Compaq, or Digital Equipment Corporation.
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Analysis
by VulDB Data Team • 01/02/2020
The vulnerability identified as CVE-2017-17482 represents a critical buffer overflow flaw within the OpenVMS operating system family that affects multiple processor architectures including Alpha, IA64, and VAX. This issue stems from improper handling of malformed DCL (Digital Command Language) command tables during command line processing, creating a pathway for local privilege escalation attacks. The vulnerability exists across various OpenVMS versions including V8.4-2L2 for Alpha systems, V8.4-2L1 for IA64 systems, and VAX/VMS 4.0 and later releases, demonstrating the widespread nature of this security weakness. The flaw specifically manifests when a non-privileged user executes a crafted command line that contains malformed DCL command table entries, allowing the attacker to overwrite adjacent memory buffers and potentially execute arbitrary code with elevated privileges.
The technical exploitation of this vulnerability involves manipulating DCL command table structures to trigger a buffer overflow condition that can be leveraged to escalate privileges from standard user level to system level access. This type of vulnerability maps directly to CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios. The attack vector requires local system access and leverages the operating system's command line parsing mechanisms to execute malicious code. On VAX and Alpha systems, the overflow can be successfully exploited to achieve privilege escalation, while IA64 systems may experience process crashes without successful privilege escalation. The vulnerability affects all implementations of OpenVMS regardless of the vendor distribution channel, indicating that the flaw exists at the core operating system level rather than being specific to particular hardware or software implementations.
The operational impact of CVE-2017-17482 extends beyond simple privilege escalation to potentially compromise entire system integrity and availability. A successful exploitation could allow attackers to gain root access to systems running affected OpenVMS versions, enabling them to modify system files, install malicious software, access sensitive data, or establish persistent backdoors. The vulnerability's presence across multiple processor architectures and version ranges means that organizations with legacy systems running OpenVMS face significant risk exposure, particularly in environments where system administrators may not be aware of the specific version and architecture combinations affected. System crashes on IA64 platforms during exploitation attempts could also lead to denial of service conditions, affecting availability alongside confidentiality and integrity concerns.
Organizations affected by this vulnerability should implement immediate mitigations including applying official security patches from HPE, which was the primary vendor maintaining OpenVMS following the acquisition by HP, and implementing additional access controls to limit local system access. The principle of least privilege should be enforced by restricting user accounts from executing potentially dangerous commands and implementing monitoring for unusual command line executions. System administrators should also consider disabling unnecessary DCL command processing capabilities and implementing robust logging mechanisms to detect potential exploitation attempts. From an ATT&CK framework perspective, this vulnerability maps to technique T1068, which involves the exploitation of privilege escalation vulnerabilities, and T1059, which covers command and scripting interpreters. The vulnerability also aligns with T1499, concerning network denial of service attacks, due to the potential for process crashes on IA64 systems. Long-term mitigation strategies should include comprehensive system inventory management to identify all affected OpenVMS installations and implementation of regular security assessments to detect similar vulnerabilities in legacy systems.