Microsoft's December security update contains another reminder that old, system-level services can still be an attractive target for attackers: CVE-2025-62474 is an
elevation of privilege vulnerability affecting the Windows Remote Access Connection Manager (RasMan) component, and system administrators should treat it as a priority item during December patching windows.
Overview
CVE-2025-62474 is reported as an
Improper Access Control elevation-of-privilege flaw in the Windows Remote Access Connection Manager (RasMan) service. The weakness allows a local, authorized user to perform operations that should be restricted, potentially enabling code or actions to run with SYSTEM-level privileges. The issue was disclosed as part of Microsoft’s December security updates and appears listed in Microsoft’s Security Update Guide under the CVE identifier for administrators to review.
Early public reporting places this RasMan issue alongside a cluster of related Windows networking and connectivity fixes in the December 2025 patch set. Multiple independent security trackers and community roundups list CVE-2025-62474 as an important-rated elevation-of-privilege flaw affecting RasMan; however, some technical details vary across early reports. Where source material differs or is incomplete, this article flags uncertainty and recommends treating Microsoft’s advisory and vendor-supplied patch notes as the authoritative reference for final remediation steps.
Background: why RasMan matters
The
Remote Access Connection Manager (RasMan) service is the Windows component responsible for managing dial-up and VPN connections and supporting legacy remote-access APIs and services. While many modern environments no longer rely on dial-up, RasMan remains present on a wide range of Windows client and server builds for backward compatibility and VPN support.
Because RasMan runs with elevated privileges and mediates networking and service control operations, any
improper access control in its code can be leveraged by a local attacker to escalate privileges. In practical terms, that makes RasMan a high-value target for attackers with an initial foothold on an endpoint: they only need local code execution at low privilege to attempt privilege escalation into SYSTEM and then pursue persistence, credential theft, or lateral movement.
Key reasons RasMan vulnerabilities are critical:
- RasMan runs with high privileges and touches networking and authentication surfaces.
- Local privilege escalation (LPE) is a common step in post-compromise escalation chains.
- RasMan is widely present across supported Windows client and server versions, increasing the blast radius.
Technical summary and verifiable facts
- Affected component: Remote Access Connection Manager (RasMan).
- CVE identifier: CVE-2025-62474, disclosed as part of Microsoft’s December 2025 updates.
- Vulnerability type: Improper access control / elevation of privilege inside RasMan.
- Exploitation vector: Local (an attacker needs local code execution or a low-privileged account on the machine).
- Remediation: Install the Microsoft security update published in the December 2025 release cycle that addresses this CVE.
Important verification notes:
- Microsoft’s Security Update Guide lists CVE-2025-62474 under the December updates for Windows RasMan; administrators should confirm the exact affected builds and KB numbers on the Microsoft portal when planning deployments.
- Public reporting around December 9, 2025, grouped this RasMan CVE with several other networking-related fixes; early technical write-ups describe improper access control as the root cause for CVE-2025-62474, whereas other RasMan CVEs in the same release cycle mention use of uninitialized resource or improper privilege management for separate IDs. These nuances indicate multiple, distinct RasMan issues were fixed across the release — treat each CVE as a distinct bug with potentially different exploitation details.
- Some community trackers assign high severity (for example, CVSS 7.8 or equivalent) to RasMan elevation-of-privilege bugs in this release set. Where official Microsoft CVSS values or full technical write-ups are not yet published, organizations should be conservative and prioritize patching.
What the vulnerability enables — attack scenarios
This class of RasMan access-control weakness enables several realistic attacker scenarios:
- Local privilege escalation (LPE): An attacker who can run code as a standard user or has compromised a low-privilege service account can leverage the flaw to obtain SYSTEM privileges on the endpoint. SYSTEM privileges permit deep system modification, credential access, and persistence mechanisms that are otherwise blocked to normal accounts.
- Post-exploitation consolidation: LPEs are frequently chained with initial phishing or remote code execution footholds. After achieving SYSTEM, attackers can disable security tooling, install kernel/root-level components, dump credential stores, or harvest domain credentials.
- Lateral movement and domain impact: If SYSTEM access is obtained on a domain-joined server or administrative workstation, attackers can attempt to escalate or reuse credentials to pivot toward identity and infrastructure targets such as domain controllers, file servers, and backup systems.
- Persistence and obfuscation: SYSTEM-level control makes it easier for an attacker to create stealthy persistence (signed driver loading, kernel hooks, scheduled tasks under SYSTEM, or modifying boot-time components) that evade routine endpoint protection.
Even though the exploitation vector is local, the practical impact is high because LPEs are a predictable post-compromise step in many intrusion cases.
Affected platforms and scope considerations
Microsoft’s December security update cycle addressed a range of Windows versions. Typical coverage for RasMan fixes includes supported builds of:
- Windows 10 and Windows 11 (various feature-update channels and builds)
- Windows Server (multiple supported releases)
- Legacy supported server releases covered by Extended Security Updates only
Administrators must confirm the exact list of affected OS builds and the specific KB/KB articles for their environment via the Microsoft Security Update Guide or the Microsoft Update Catalog before applying patches in production. Where organizations run unsupported or out-of-support Windows versions, special attention is required: Extended Security Updates (ESU) customers may receive fixes, while others may need compensating controls.
Exploitation status and confidence
- Early reporting in community roundups and vulnerability trackers places this RasMan CVE in the December 9 patch set.
- Some RasMan-related CVEs in 2025 were reported as exploited in the wild or exploitation detected; however, for CVE-2025-62474 specifically, public exploitation telemetry varies across sources. Treat any early exploitation reports as high-priority but verify exploitation status with vendor advisories and security intelligence feeds tied to your organization.
- Confidence in the existence of the vulnerability is high (Microsoft acknowledged the ID in its update guide). The exact exploitability details (e.g., published PoC, in-the-wild campaigns, or attack chains) should be validated against vendor intelligence and reputable third-party trackers.
Cautionary note: public trackers sometimes consolidate multiple RasMan issues (different CVE IDs) or report differing root causes. Where exploitation status matters for prioritization, use confirmed telemetry (EDR detections, threat intelligence, Microsoft Exploitability Index statements) rather than aggregated headlines.
How to prioritize and deploy the fix (practical patching guidance)
- Inventory and identify:
- Use patch management tools (WSUS, Microsoft Endpoint Manager, SCCM/ConfigMgr) to map CVE-2025-62474 to your installed Windows builds.
- Flag all endpoints that run RasMan-reliant functionality (VPN gateways, legacy dial-up components, and devices that provide remote access functions).
- Test in lab:
- Apply the December security update to representative test systems before wide deployment.
- Validate functionality for VPN and remote access clients; RasMan fixes should be backward-compatible, but complex network stacks sometimes show regressions in niche configurations.
- Staged rollout:
- Deploy to high-priority, high-exposure systems (administrative workstations, jump boxes, domain controllers if applicable) after successful tests.
- Monitor telemetry for regressions (service failures, authentication errors, or VPN disconnects).
- Full deployment:
- Roll out to all endpoints as soon as practical; for large organizations, follow the established change-control windows but avoid unnecessary delays on systems exposed to user activity or insider risk.
- Post-deployment verification:
- Confirm update installation via patch management reporting and Windows Update compliance metrics.
- Review logs for unexpected service restarts, driver load failures, or other anomalies and roll back if needed only after analysis.
Important operational notes:
- If RasMan functionality is not required in a given environment, consider disabling the RasMan service as a temporary mitigation, but only after confirming that no business processes or managed VPNs depend on it.
- Ensure the latest servicing stack updates (SSU) are applied before feature/security updates to prevent update failures.
Detection and hunting guidance
To detect potential exploitation attempts and follow-on activity, instrument systems and your SIEM with the following controls and hunts:
- Audit key Windows security events:
- 4688 (A new process has been created): enable process creation auditing with command-line logging. Hunt for unexpected processes spawned by rasman.exe or processes that change token elevation.
- 4672 (Special privileges assigned to new logon): monitor for abnormal assignments of sensitive privileges to non-standard accounts.
- 7045 (A service was installed) and Service Control Manager events: watch for unauthorized service installation or manipulation of RasMan-related services.
- Watch rasman.exe behavior:
- Monitor binary image loads, DLLs loaded into RasMan’s process space, and any writes to the RasMan installation directories (e.g., C:\Windows\System32\ras*). Sudden modifications or unsigned DLL loads are suspicious.
- Alert on rasman.exe launching unexpected child processes or spawning command interpreters under elevated tokens.
- EDR and endpoint telemetry:
- Use EDR to capture file writes, registry changes, and kernel-mode driver loads around RasMan activity. Correlate with LPE indicators such as token replacement, SeAssignPrimaryTokenPrivilege, or driver installation under SYSTEM context.
- Search for unusual use of APIs commonly abused in LPE exploits (token manipulation, duplicate handle elevation patterns) if your telemetry supports such detection.
- Hunt for persistence and lateral movement:
- After LPE, attackers often create persistences (scheduled tasks, services, registry run keys); scan for new service entries, unexpected scheduled tasks, and changes to autostart locations.
- Prioritize investigation of endpoints with both signs of RasMan manipulation and abnormal network traffic to internal domains or suspicious external endpoints.
- Use file integrity monitoring:
- Alert on changes to core system binaries and on the presence of unfamiliar files in system directories.
Temporary mitigations and hardening (if patching is delayed)
If you cannot apply the security update immediately, consider temporary mitigations and defensive hardening:
- Disable RasMan if not required:
- Stop and set the RasMan service to Disabled on endpoints that do not require dial-up or legacy VPN functionality. Note this may break VPN solutions that rely on RasMan—coordinate with networking teams.
- Strengthen local account policies:
- Restrict local interactive logins and minimize the number of local admin accounts. Use tiered administration models to limit where low-privileged users can authenticate.
- Reduce attack surface:
- Apply AppLocker or Windows Defender Application Control (WDAC) policies where possible to prevent unauthorized code execution and inhibit ad-hoc PoC exploitation.
- Credential protections:
- Enable Windows Defender Credential Guard and LSA protection features where supported to make credential theft more difficult after an LPE.
- Privilege separation:
- Enforce least privilege for user sessions and use Just Enough Administration (JEA) or Privileged Access Workstations (PAWs) to limit exposure of high-value administrative credentials.
These are stop-gap measures; only applying Microsoft’s fix fully addresses the vulnerability at its root.
Indicators of compromise (IoCs) — what to look for
Typical signs that a RasMan elevation-of-privilege exploit may have been attempted or succeeded:
- Unexpected service modifications, new service installations, or service-related Event ID 7045 entries tied to unusual binaries.
- Process creation (Event ID 4688) where rasman.exe or related system processes spawn command shells, PowerShell, or run unsigned binaries.
- Event ID 4672 occurrences that show high-privilege assignments tied to unusual accounts or non-standard logon sessions.
- New or modified files in system folders (System32) with odd timestamps, or the presence of unsigned DLLs loading into system processes.
- EDR detections showing token manipulation, process injection, or suspicious driver load events around the time of RasMan activity.
When investigating, preserve volatile evidence (memory, process lists, running handles) and collect full timeline data to determine whether an LPE resulted in persistent compromise.
Risk assessment and enterprise impact
- Business impact: High for systems that act as administrative workstations, file servers, or that store domain credentials; medium for isolated client machines.
- Likelihood: Moderate to high in environments where attackers can obtain local access (phishing, remote code execution in other software, or compromised low-privilege accounts).
- Exploit complexity: Public reports list RasMan privilege issues in the December set as low attack complexity when the attacker has local access, making them attractive to threat actors.
- Attack surface: Broad — RasMan exists on most Windows endpoints and servers, increasing the number of targets that require patching.
A single successful LPE can convert a foothold into full host compromise. In the context of an advanced adversary, the vulnerability can materially increase the chance of domain compromise if used in combination with credential access and lateral movement techniques.
Post-patch verification checklist
After applying the Microsoft update for CVE-2025-62474, perform the following checks:
- Confirm installation:
- Use your patch reporting tools, or query the system’s update history to confirm the December 2025 update and relevant KBs are installed.
- Validate RasMan behavior:
- Test VPN/remote access connections and any custom applications that rely on RasMan APIs.
- Verify the RasMan service starts and stops normally and there are no unusual errors logged in the System and Application logs.
- Re-run detections:
- Re-scan endpoints for the IoCs listed above to ensure no lingering compromise indicators are present.
- Review EDR alerts:
- Check prior alerts for potential exploitation attempts and investigate any correlated activity that could indicate a pre-patch compromise.
- For confirmed compromise:
- If you find evidence of exploitation or suspicious system modifications, follow incident response procedures: isolate affected hosts, capture forensic artifacts (memory, disk images), reset credentials of impacted accounts, and perform aggressive domain-level credential and trust validation.
Final analysis: strengths, uncertainties, and risk posture
Strengths in the response:
- Microsoft included RasMan fixes in a coordinated December update, enabling administrators to remediate across supported builds with vendor-supplied patches.
- Public reporting has rapidly cataloged the CVEs and raised awareness, improving the speed of enterprise patching efforts.
Uncertainties and risks:
- Early reporting around the RasMan set shows multiple CVEs with overlapping descriptions (improper access control, use of uninitialized resource, improper privilege management). This creates the risk of misclassification; administrators must match the exact CVE ID to the installed KB and affected OS builds rather than assuming all RasMan fixes are identical.
- Exploitation telemetry for CVE-2025-62474 specifically varies across sources. Treat unconfirmed claims of in-the-wild exploitation with caution until corroborated by vendor or trusted threat-intel teams.
- Environments that cannot patch quickly (due to legacy software dependencies) remain at elevated risk and should implement the mitigation steps outlined above.
Bottom line: treat CVE-2025-62474 as a high-priority local privilege escalation risk on Windows endpoints where RasMan is present. Apply the December 2025 update from Microsoft following standard testing and change-control processes. If immediate patching is impossible, harden endpoints, limit local account usage, and increase detection and monitoring for the IoCs described.
Action plan (concise, prioritized)
- Identify all Windows systems that require the December 2025 updates and map which are affected by RasMan fixes.
- Test the vendor-supplied update in a representative lab environment.
- Stage a phased rollout: critical/high-exposure systems first, then broad deployment.
- Strengthen detection: enable process creation and special-privilege auditing (Event IDs 4688, 4672), deploy targeted EDR hunts for rasman-related anomalies.
- Implement immediate mitigations where needed: disable RasMan on systems that do not require it, or apply application control to prevent unauthorized code execution.
- Investigate unusual pre-patch activity and treat confirmed exploitation as an incident requiring containment, forensics, and possible credential resets.
CVE-2025-62474 highlights a persistent truth: legacy services embedded in modern OS builds can still be exploited as Windows continues to carry backward-compatible components. Rapid, coordinated patching, combined with layered detection and least-privilege practices, is the best defense against this class of elevation-of-privilege threats.
Source: MSRC
Security Update Guide - Microsoft Security Response Center