CVE-2025-47987 Overview
CVE-2025-47987 is a heap-based buffer overflow [CWE-122] in the Windows Cred SSProvider Protocol. An authorized local attacker can exploit the flaw to elevate privileges on affected Microsoft Windows client and server systems. Microsoft published the advisory on July 8, 2025, and the vulnerability affects Windows 10, Windows 11, and Windows Server editions ranging from Server 2008 through Server 2025.
The issue requires local access and low privileges but no user interaction. Successful exploitation yields high impact to confidentiality, integrity, and availability. The EPSS score is 1.677% at the 74th percentile, indicating moderate exploitation likelihood relative to other published CVEs.
Critical Impact
Local privilege escalation to higher-integrity contexts, enabling attackers to bypass standard user restrictions and execute privileged operations on the affected Windows host.
Affected Products
- Microsoft Windows 10 (versions 1507, 1607, 1809, 21H2, 22H2)
- Microsoft Windows 11 (versions 22H2, 23H2, 24H2)
- Microsoft Windows Server 2008, 2012, 2016, 2019, 2022, 2022 23H2, and 2025
Discovery Timeline
- 2025-07-08 - CVE-2025-47987 published to NVD and Microsoft security advisory released
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-47987
Vulnerability Analysis
The vulnerability resides in the Windows Cred SSProvider Protocol, a component tied to credential handling through the Credential Security Support Provider (CredSSP) surface. A heap-based buffer overflow occurs when the protocol handler processes attacker-controlled input without enforcing correct bounds on a heap allocation. This condition allows adjacent heap metadata or object fields to be overwritten.
An authorized local user can craft input that triggers the overflow during credential processing. By shaping the heap and controlling the overwritten data, the attacker can corrupt function pointers or object state used by a higher-privileged context. The result is arbitrary code execution or privilege escalation on the affected host.
Root Cause
The root cause is improper validation of a length or size value before copying data into a heap buffer, classified as [CWE-122] heap-based buffer overflow. When the source data exceeds the allocated buffer, adjacent heap regions are overwritten, corrupting protocol state or control data.
Attack Vector
Exploitation requires local access with valid low-privileged credentials. The attacker interacts with the vulnerable Cred SSProvider component from a standard user session, sending malformed requests that trigger the overflow. No user interaction is required. Microsoft does not report exploitation in the wild, and CISA has not added this CVE to the Known Exploited Vulnerabilities catalog.
Detailed exploitation code is not publicly documented in the NVD or Microsoft advisory. Refer to the Microsoft Security Update CVE-2025-47987 advisory for vendor guidance.
Detection Methods for CVE-2025-47987
Indicators of Compromise
- Unexpected crashes or exception events in lsass.exe or processes hosting CredSSP components on affected Windows hosts.
- Windows Error Reporting entries referencing heap corruption in credential-related modules.
- Anomalous process creation from low-privileged user sessions spawning SYSTEM or elevated processes.
Detection Strategies
- Monitor Sysmon Event ID 1 (process creation) and Event ID 10 (process access) for suspicious parent-child relationships involving credential provider processes.
- Correlate application crash events (Event ID 1000) with subsequent privilege elevation activity on the same host.
- Deploy behavioral endpoint detection to flag heap corruption exploit patterns targeting Windows authentication components.
Monitoring Recommendations
- Enable audit policies for privilege use (Audit Sensitive Privilege Use) and account logon events across all affected Windows systems.
- Baseline normal CredSSP activity in enterprise environments to identify deviations that may indicate exploitation attempts.
- Ingest Windows Security and Application logs into a centralized SIEM for correlation and long-term retention.
How to Mitigate CVE-2025-47987
Immediate Actions Required
- Apply the Microsoft security update referenced in the Microsoft Security Update CVE-2025-47987 advisory to all affected Windows hosts.
- Prioritize patching for multi-user systems, terminal servers, and jump hosts where local user access is common.
- Review and restrict local user accounts on domain controllers and privileged infrastructure.
Patch Information
Microsoft released security updates addressing CVE-2025-47987 on July 8, 2025, as part of the monthly Patch Tuesday cycle. Consult the Microsoft Security Update CVE-2025-47987 advisory for the specific KB article and update package matching each Windows build.
Workarounds
- No official workaround has been published by Microsoft. Applying the security update is the required remediation path.
- Reduce exposure by enforcing least privilege and limiting interactive logon rights on sensitive systems until patches are deployed.
- Monitor CredSSP-related telemetry and restrict unnecessary local accounts on critical hosts.
# Verify installed updates on Windows (PowerShell)
Get-HotFix | Sort-Object -Property InstalledOn -Descending | Select-Object -First 20
# Trigger Windows Update scan and install
UsoClient StartScan
UsoClient StartDownload
UsoClient StartInstall
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
