CVE-2022-24504: Windows 10 PPTP RCE Vulnerability

CVE-2022-24504 Overview

CVE-2022-24504 is a remote code execution vulnerability in the Windows Point-to-Point Tunneling Protocol (PPTP) implementation. The flaw stems from a race condition [CWE-362] in the protocol handler, which an unauthenticated remote attacker can exploit to execute arbitrary code on affected systems. Microsoft addressed the issue in the October 2022 Patch Tuesday cycle. The vulnerability affects a broad range of Windows client and server editions, including Windows 7 through Windows 11 and Windows Server 2008 through Windows Server 2022.

Critical Impact

Successful exploitation grants remote attackers the ability to execute arbitrary code on vulnerable Windows hosts running PPTP services, potentially leading to full system compromise.

Affected Products

• Microsoft Windows 10 (all supported builds, x86/x64/ARM64)
• Microsoft Windows 11 (including 22H2)
• Microsoft Windows 7 SP1, Windows 8.1, and Windows RT 8.1
• Microsoft Windows Server 2008 SP2, 2008 R2, 2012, 2012 R2, 2016, 2019, and 2022

Discovery Timeline

• 2022-10-11 - CVE-2022-24504 published to NVD as part of Microsoft's October 2022 security update
• 2025-01-02 - Last updated in NVD database

Technical Details for CVE-2022-24504

Vulnerability Analysis

The vulnerability resides in the Windows PPTP service, which provides legacy virtual private network (VPN) tunneling over TCP port 1723 and GRE. PPTP is used to establish remote access connections between clients and a Routing and Remote Access Service (RRAS) server. The defect is a race condition that an attacker can trigger by sending specially crafted PPTP control messages to a vulnerable endpoint. Because the issue lies in the protocol handler itself, no authentication or user interaction is required to reach the vulnerable code path. Successful exploitation results in arbitrary code execution in the context of the vulnerable PPTP service.

Root Cause

The underlying weakness is a concurrent execution flaw classified as [CWE-362] (Race Condition). Two or more threads or operations within the PPTP service access shared state without proper synchronization. An attacker who can influence the timing of concurrent PPTP requests can reach an inconsistent state that the service then operates on, leading to memory corruption and control-flow hijacking.

Attack Vector

The attack vector is network-based. An attacker who can reach the PPTP listener (typically TCP/1723) on a Windows host that has the RRAS or PPTP server role enabled can send crafted control packets to exploit the race window. Exploitation complexity is high because the attacker must win a race condition reliably, which reduces opportunistic mass exploitation but does not eliminate targeted abuse against exposed PPTP endpoints. There are no public proof-of-concept exploits associated with this CVE, and it is not listed in the CISA Known Exploited Vulnerabilities catalog.

No verified public exploit code is available for CVE-2022-24504. Refer to the Microsoft CVE-2022-24504 Advisory for vendor-supplied technical detail.

Detection Methods for CVE-2022-24504

Indicators of Compromise

• Unexpected inbound traffic on TCP port 1723 or GRE protocol (IP protocol 47) to hosts that should not be running PPTP
• PPTP service (RemoteAccess, RasMan) crashes, restarts, or unexpected child process creation tied to RRAS
• New or unknown local accounts or services appearing on RRAS servers following anomalous PPTP traffic

Detection Strategies

• Monitor Windows Event Logs for RRAS service crashes and abnormal restart patterns on systems that expose PPTP
• Inspect network telemetry for malformed or fragmented PPTP control messages and unusually high connection rates to TCP/1723
• Correlate PPTP connection events with subsequent process creation, network connections, or credential access on the same host

Monitoring Recommendations

• Inventory hosts with the RRAS role enabled and alert on any new exposure of TCP/1723 to untrusted networks
• Enable PowerShell, process creation (Event ID 4688), and Sysmon logging on RRAS servers and forward to a centralized analytics platform
• Baseline normal PPTP client populations and alert on connections from previously unseen source addresses or geographies

How to Mitigate CVE-2022-24504

Immediate Actions Required

• Apply the Microsoft October 2022 security updates to all affected Windows client and server SKUs
• Identify any internet-exposed PPTP endpoints and restrict access until patching is verified
• Audit the RRAS configuration and disable PPTP if it is not required for business operations

Patch Information

Microsoft released fixes for CVE-2022-24504 in the October 11, 2022 security update cycle. Patch availability and KB article numbers per Windows version are documented in the Microsoft CVE-2022-24504 Update Guide and the Microsoft Security Advisory. Administrators should validate that the corresponding monthly rollup or security-only update is installed on every affected system.

Workarounds

• Block inbound TCP/1723 and GRE (IP protocol 47) at the network perimeter where PPTP is not explicitly required
• Migrate remote access users from PPTP to a modern VPN protocol such as IKEv2 or SSTP and disable the PPTP server role
• Restrict PPTP listener exposure to dedicated management VLANs or IP allow-lists until patches are deployed

# Disable the PPTP server role on Windows RRAS hosts (run elevated)
Set-Service -Name RemoteAccess -StartupType Disabled
Stop-Service -Name RemoteAccess -Force

# Block PPTP control channel at the host firewall
New-NetFirewallRule -DisplayName "Block PPTP 1723 Inbound" -Direction Inbound -Protocol TCP -LocalPort 1723 -Action Block