CVE-2017-0213 is a privilege escalation vulnerability in Microsoft Windows. CISA added it to the Known Exploited Vulnerabilities catalogue on 28 March 2022, which means attackers have used it in real attacks. Microsoft Windows COM Aggregate Marshaler allows for privilege escalation when an attacker runs a specially crafted application.
What this vulnerability means in practice
CVE-2017-0213 is a Windows privilege escalation flaw, so the security issue is not initial access but turning a foothold into higher authority. In practice, that makes it attractive after phishing, drive-by execution, or any other route that lets an attacker run code on a target host.
The weakness sits in Microsoft Windows COM Aggregate Marshaler. When an attacker can run a specially crafted application, the flaw can let that code cross a privilege boundary and act with more power than it should. That is the core danger of local privilege escalation: one compromised user context becomes a platform for broader host compromise.
Why privilege escalation changes the blast radius
Privilege escalation is especially dangerous because it lets an attacker move from limited execution to actions that affect the whole system. Once elevated, the attacker can tamper with security tools, harvest more data, stage persistence, or use the system as a pivot point for lateral movement.
That escalation also changes the identity impact. If the compromised session belongs to a user with access to cached credentials, tokens, scripts, or administrative tooling, the exploit can expose more than the local machine. It can become a route to additional accounts and systems.
The risk is amplified when Windows hosts are used for administration, software deployment, or sensitive business workflows. A single vulnerable endpoint can then become a stepping stone into broader enterprise access.
How organisations assess exposure and reduce impact
Exposure checks start with inventory: which Windows systems are in scope, which ones are internet-facing or remotely reachable, and which ones are running software that could deliver a crafted payload. Vendor advisories and the CISA KEV catalogue should be used to confirm urgency and patch guidance for the exact environment.
If patching is delayed, compensating controls matter. Reduce local administrative use, limit the ability to run untrusted applications, and harden endpoints so that privilege boundaries are harder to abuse. Where possible, isolate high-value Windows systems and restrict who can log on interactively or remotely.
Because the exploit requires code execution on the host, prevention and containment are both relevant. Application control, least privilege, and aggressive endpoint hardening do not remove the flaw, but they can make successful exploitation much harder and limit the value of a compromise.
Detection, response, and post-exploitation review
Detection should focus on the behavior after exploitation, not only the CVE itself. Look for suspicious process creation, unexpected parent-child process relationships, privilege changes, and security tooling being disabled or tampered with. These are common signs that a local exploit has been used to gain stronger execution authority.
After patching, review the host as if it may already have been used as an entry point. That means checking for persistence mechanisms, unusual scheduled tasks or services, and any evidence that credentials or tokens were accessed after elevation. The goal is not just to close the vulnerability, but to confirm the machine was not already turned into a launchpad for further compromise.
Risk and Threat Considerations
This vulnerability matters because it turns ordinary code execution into a pathway for system-level control. Attackers do not need it to be remotely exploitable to use it effectively, since privilege escalation often follows some earlier foothold on the host.
Failure mechanism: A specially crafted application abuses the Windows COM Aggregate Marshaler boundary and causes the process to run with higher privilege than intended.
Impact: A successful exploit can expand an attacker’s control over the endpoint, weaken defensive visibility, and enable credential access, persistence, or lateral movement.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
MITRE ATT&CK addresses the attack and risk surface, while NIST SP 800-53 Rev 5 sets the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST SP 800-53 Rev 5 | IA-2 — Identification and Authentication (Organizational Users) | Windows privilege escalation often starts after user authentication, then abuses the session. |
| AC-6 — Least Privilege | The CVE escalates privileges beyond intended authority, directly implicating least privilege. | |
| SI-2 — Flaw Remediation | This is a software vulnerability that requires timely remediation and verification. | |
| Recommendation — Tighten organizational user authentication and separate standard from privileged logon paths. Restrict user and process rights so compromised code cannot gain unnecessary authority. Track the flaw, apply the vendor fix, and verify vulnerable systems are fully remediated. | ||
| MITRE ATT&CK | T1068 — Exploitation for Privilege Escalation | The term describes an exploit used to raise local privileges on Windows. |
| T1548 — Abuse Elevation Control Mechanism | The exploit abuses a Windows elevation mechanism to cross a privilege boundary. | |
| Recommendation — Map observed activity to privilege-escalation behavior and hunt for follow-on abuse. Review elevation paths and alert on suspicious use of privileged execution mechanisms. | ||
Practitioner Guidance
Why practitioners should care: Treat this as an endpoint privilege boundary issue, not just a patching item. The practical question is whether any Windows system that can run untrusted or user-controlled code can still be used to gain higher authority.
What to watch for: Prioritise systems where users have meaningful local access, where administrative activity is common, or where a compromised workstation could expose privileged sessions or management tooling. Those are the places where a local exploit has the highest operational value.
Related resources from NHI Mgmt Group
- CVE-2017-0005 (Microsoft Windows Graphics Device Interface (GDI) Privilege Escalation)
- CVE-2014-1812 (Microsoft Windows Group Policy Preferences Password Privilege Escalation)
- CVE-2019-1388 (Microsoft Windows Certificate Dialog Privilege Escalation)
- CVE-2024-38107 (Microsoft Windows Power Dependency Coordinator Privilege Escalation)