CVE-2025-29832: Windows 10 Information Disclosure Flaw

CVE-2025-29832 Overview

CVE-2025-29832 is an out-of-bounds read vulnerability [CWE-125] in the Windows Routing and Remote Access Service (RRAS). The flaw allows an unauthorized attacker to disclose information over a network. Exploitation requires user interaction, and the attack vector is network-based with low attack complexity. Microsoft published the advisory on May 13, 2025, and the CVE affects a broad range of Windows client and server versions, including Windows 10, Windows 11, and Windows Server 2008 through Windows Server 2025.

Critical Impact
Successful exploitation leaks the contents of process memory from a system running RRAS, potentially exposing sensitive data used to escalate follow-on attacks against the network.

Affected Products

Microsoft Windows 10 (1507, 1607, 1809, 21H2, 22H2) on x86, x64, and ARM64
Microsoft Windows 11 (22H2, 23H2, 24H2) on x64 and ARM64
Microsoft Windows Server 2008, 2012, 2016, 2019, 2022, 2022 23H2, and 2025

Discovery Timeline

2025-05-13 - Microsoft releases security patch for CVE-2025-29832
2025-05-13 - CVE-2025-29832 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-29832

Vulnerability Analysis

The Routing and Remote Access Service (RRAS) provides routing, VPN, and dial-up services on Windows hosts. The service processes network-facing protocol traffic, including PPP, PPTP, L2TP, and IKE messages, along with associated management interfaces. An out-of-bounds read in this parsing surface returns memory contents that lie beyond the intended buffer boundary.

When the attacker-controlled message triggers the read, RRAS returns bytes from adjacent memory regions to the caller. Those bytes can contain protocol state, session identifiers, credentials, cryptographic material, or heap metadata. The information can be re-used to plan further intrusion steps against the same or connected hosts.

Exploitation requires user interaction, which in practice means an administrator or user must initiate an action that causes the vulnerable code path to run against attacker-supplied data. This can occur when a system connects to a malicious remote peer.

Root Cause

The root cause is missing or insufficient bounds checking on a length or offset field within an RRAS-parsed structure. The service reads past the end of an allocated buffer [CWE-125] and returns the resulting bytes through the protocol response path.

Attack Vector

The attack is delivered over the network. An attacker sends a crafted RRAS message to a target that has RRAS enabled, or induces a target to connect to an attacker-controlled RRAS endpoint. Because the service is not enabled by default on client Windows editions, exposure is concentrated on servers configured as VPN or routing gateways.

No verified public exploit code is available for CVE-2025-29832 at the time of publication. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. The EPSS score is 1.042%.

Detection Methods for CVE-2025-29832

Indicators of Compromise

Unexpected inbound connections to TCP/UDP ports associated with RRAS (for example, PPTP 1723, L2TP/IPsec 1701/500/4500) from untrusted sources.
RRAS service crashes, restarts, or Windows Error Reporting entries referencing mprdim.dll, rasmans.dll, or related RRAS modules.
Outbound connections from Windows Servers configured as VPN gateways to previously unseen external endpoints after a user-initiated action.

Detection Strategies

Alert on Windows Event Log entries in the System and RemoteAccess channels that show abnormal RRAS session negotiation failures or repeated malformed packets.
Deploy IDS/IPS signatures that inspect RRAS protocol traffic for malformed length fields and truncated headers targeting ports 1701, 1723, 500, and 4500.
Correlate RRAS process telemetry with unexpected memory reads or handle activity using EDR behavioral analytics.

Monitoring Recommendations

Inventory all hosts with the RemoteAccess role installed and monitor their patch state against the Microsoft May 2025 security update.
Log and review administrative changes to RRAS configuration and VPN peer definitions.
Capture network flow data at perimeter and internal VPN concentrators to establish a baseline for RRAS traffic volume and peers.

How to Mitigate CVE-2025-29832

Immediate Actions Required

Apply the Microsoft May 2025 security update for every affected Windows client and server SKU listed in the advisory.
Identify all servers running the Routing and Remote Access role and prioritize them for patch deployment.
If patching must be delayed, disable RRAS on hosts that do not require it and restrict inbound RRAS traffic at the firewall.

Patch Information

Microsoft released fixed builds on May 13, 2025. Refer to the Microsoft Security Update CVE-2025-29832 advisory for the specific KB article and package matching each Windows version. Windows Server 2008 and 2012 require the corresponding Extended Security Update (ESU) package.

Workarounds

Disable the Routing and Remote Access service on hosts that do not act as VPN or routing gateways.
Restrict RRAS-related ports (500/UDP, 1701/UDP, 1723/TCP, 4500/UDP) at perimeter and internal firewalls to known peers only.
Require administrators to connect only to trusted RRAS endpoints to reduce the user-interaction attack surface.

bash

# Query and disable the RRAS service on hosts that do not require it
Get-Service -Name RemoteAccess
Stop-Service -Name RemoteAccess -Force
Set-Service -Name RemoteAccess -StartupType Disabled