Yes. CISA added CVE-2023-21674 to its Known Exploited Vulnerabilities catalogue on 10 January 2023, which it does only when there is reliable evidence of active exploitation. CISA has not linked it to known ransomware campaigns. Microsoft Windows Advanced Local Procedure Call (ALPC) contains an unspecified vulnerability that allows for privilege escalation. Any organisation running the affected product should treat remediation as urgent.
What “being exploited in the wild” means for this CVE
For a CVE already listed in CISA’s Known Exploited Vulnerabilities catalogue, the practical question is no longer whether exploitation is plausible, but whether your environment still contains the vulnerable condition. That shifts the focus from abstract severity to exposure confirmation, asset ownership, and whether the affected Windows systems are still reachable, monitored, and patchable.
Because this is an operating-system privilege escalation issue, the first operational test is simple: identify every Windows host that could still carry the vulnerable condition and confirm whether it has been remediated or isolated. A catalogued exploitation case should be treated as an urgent patch-and-verify event, not a routine maintenance item.
How to confirm exposure and close the gap
The most useful response is to work from the installed base rather than the CVE headline. Validate which endpoints, servers, and virtual machines are running the affected product, then compare that inventory with your patch and exception records. If you cannot prove that a system is fixed, assume it remains a candidate for exploitation and bring it into remediation scope.
When teams delay patching, the fallback is containment, not optimism. Reduce exposure by tightening administrative access, limiting remote reachability, and watching for unusual privilege changes on the at-risk hosts. If the vulnerable system supports sensitive services or privileged users, treat it as a higher-priority remediation target than a standard workstation.
What to check after remediation
After patching or mitigation, validate that no earlier compromise occurred during the exposure window. For a privilege escalation flaw, the key question is whether an attacker could have converted initial access into elevated rights before the fix was applied. Review sign-in anomalies, unexpected local administrators, new scheduled tasks, service creation, and suspicious process or script activity on the impacted machines.
If the host was part of a broader privileged workflow, also review whether credentials, sessions, or tokens used on that system may have been exposed during the incident window. Vulnerability Management Guide is the right internal reference for turning that review into a tracked remediation and verification workflow.
Risk and Threat Considerations
Privilege escalation vulnerabilities are attractive because they shorten the path from foothold to control. Once an attacker can raise privileges on a Windows host, they may be able to disable security tooling, access protected data, or use that system as a launching point for lateral movement. A KEV listing means that exploitation is not theoretical, so exposure should be treated as active operational risk.
Failure mechanism: an attacker with limited access abuses the local privilege escalation condition to gain higher rights on the host, then uses those rights to persist, evade detection, or move deeper into the environment.
Impact: the host can become a pivot point for broader compromise, including credential theft, tampering with system protections, and expansion into adjacent systems or administrative workflows.
What “being exploited in the wild” means for this CVE
For a CVE already listed in CISA’s Known Exploited Vulnerabilities catalogue, the practical question is no longer whether exploitation is plausible, but whether your environment still contains the vulnerable condition. That shifts the focus from abstract severity to exposure confirmation, asset ownership, and whether the affected Windows systems are still reachable, monitored, and patchable.
Because this is an operating-system privilege escalation issue, the first operational test is simple: identify every Windows host that could still carry the vulnerable condition and confirm whether it has been remediated or isolated. A catalogued exploitation case should be treated as an urgent patch-and-verify event, not a routine maintenance item.
How to confirm exposure and close the gap
The most useful response is to work from the installed base rather than the CVE headline. Validate which endpoints, servers, and virtual machines are running the affected product, then compare that inventory with your patch and exception records. If you cannot prove that a system is fixed, assume it remains a candidate for exploitation and bring it into remediation scope.
When teams delay patching, the fallback is containment, not optimism. Reduce exposure by tightening administrative access, limiting remote reachability, and watching for unusual privilege changes on the at-risk hosts. If the vulnerable system supports sensitive services or privileged users, treat it as a higher-priority remediation target than a standard workstation.
What to check after remediation
After patching or mitigation, validate that no earlier compromise occurred during the exposure window. For a privilege escalation flaw, the key question is whether an attacker could have converted initial access into elevated rights before the fix was applied. Review sign-in anomalies, unexpected local administrators, new scheduled tasks, service creation, and suspicious process or script activity on the impacted machines.
If the host was part of a broader privileged workflow, also review whether credentials, sessions, or tokens used on that system may have been exposed during the incident window. Vulnerability Management Guide is the right internal reference for turning that review into a tracked remediation and verification workflow.
Risk and Threat Considerations
Privilege escalation vulnerabilities are attractive because they shorten the path from foothold to control. Once an attacker can raise privileges on a Windows host, they may be able to disable security tooling, access protected data, or use that system as a launching point for lateral movement. A KEV listing means that exploitation is not theoretical, so exposure should be treated as active operational risk.
Failure mechanism: an attacker with limited access abuses the local privilege escalation condition to gain higher rights on the host, then uses those rights to persist, evade detection, or move deeper into the environment.
Impact: the host can become a pivot point for broader compromise, including credential theft, tampering with system protections, and expansion into adjacent systems or administrative workflows.
Practitioner Guidance
What to prioritise: patch hosts that are internet-facing, administratively reachable, or already used by privileged staff first. A vulnerable Windows system with broad reach is more valuable to an attacker than an isolated endpoint, even if both carry the same CVE.
What to verify: confirm remediation with evidence, not ticket closure. You want an inventory view, a patch status view, and a post-change check that shows the affected systems no longer present the vulnerable condition.
Decision rule: if patching must wait, compensate with temporary isolation and tighter privilege controls, then perform compromise hunting before returning the host to normal trust. If the system handled administrative activity during the exposure period, escalate the review.
Practitioner takeaway: for a KEV-listed Windows privilege escalation issue, the real test is whether you can bound the blast radius before you can prove the patch has landed.
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 CIS Controls v8, NIST SP 800-53 Rev 5 and NIST CSF 2.0 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| CIS Controls v8 | CIS-7 — Continuous Vulnerability Management | This CVE needs rapid exposure checking, prioritised remediation, and verification. |
| Recommendation — Prioritise and verify remediation for hosts listed in the KEV catalogue. | ||
| NIST SP 800-53 Rev 5 | SI-2 — Flaw Remediation | The subject is active exploitation of a software flaw requiring urgent remediation and validation. |
| Recommendation — Track, patch, and verify the flaw-remediation cycle for affected Windows systems. | ||
| MITRE ATT&CK | T1068 — Exploitation for Privilege Escalation | The vulnerability type is local privilege escalation, matching this attack technique. |
| Recommendation — Hunt for privilege-escalation activity and validate administrative boundary abuse. | ||
| NIST CSF 2.0 | DE.CM-01 — Security Continuous Monitoring | Active exploitation calls for continuous monitoring of affected assets and compromise indicators. |
| PR.AA-05 — Authenticators are managed commensurate with the risk to the assets they protect | Privilege escalation can expose privileged access paths that should be reviewed and bounded. | |
| Recommendation — Monitor affected hosts for signs of exploitation and post-compromise change. Review and constrain privileged access paths on hosts exposed to escalation risk. | ||
Practitioner Guidance
What to prioritise: patch hosts that are internet-facing, administratively reachable, or already used by privileged staff first. A vulnerable Windows system with broad reach is more valuable to an attacker than an isolated endpoint, even if both carry the same CVE.
What to verify: confirm remediation with evidence, not ticket closure. You want an inventory view, a patch status view, and a post-change check that shows the affected systems no longer present the vulnerable condition.
Decision rule: if patching must wait, compensate with temporary isolation and tighter privilege controls, then perform compromise hunting before returning the host to normal trust. If the system handled administrative activity during the exposure period, escalate the review.
Practitioner takeaway: for a KEV-listed Windows privilege escalation issue, the real test is whether you can bound the blast radius before you can prove the patch has landed.
Related resources from NHI Mgmt Group
- Guide: Zero-Day and Exploited Vulnerabilities Guide
- CVE-2023-21674 (Microsoft Windows Advanced Local Procedure Call (ALPC) Privilege Escalation)
- Is CVE-2023-28229 (Microsoft Windows CNG Key Isolation Service Privilege Escalation) being exploited in the wild?
- Is CVE-2023-23376 (Microsoft Windows Common Log File System (CLFS) Driver Privilege Escalation) being exploited in the wild?
- Is CVE-2014-1812 (Microsoft Windows Group Policy Preferences Password Privilege Escalation) being exploited in the wild?