CVE-2025-25050: Dell ControlVault Buffer Overflow Flaw

CVE-2025-25050 Overview

CVE-2025-25050 is an out-of-bounds write vulnerability in the cv_upgrade_sensor_firmware functionality of Dell ControlVault3 and Dell ControlVault3 Plus. A local attacker with low privileges can issue a specially crafted ControlVault API call to trigger memory corruption. Successful exploitation impacts confidentiality, integrity, and availability, and can cross security boundaries due to a scope change. The flaw is tracked under CWE-787: Out-of-bounds Write and affects Dell ControlVault3 firmware prior to 5.15.10.14 and Dell ControlVault3 Plus prior to 6.2.26.36.

Critical Impact
Local attackers can corrupt firmware memory on affected Dell endpoints, enabling privilege escalation and potential persistence at the firmware layer.

Affected Products

Dell ControlVault3 firmware prior to 5.15.10.14
Dell ControlVault3 Plus firmware prior to 6.2.26.36
Dell endpoints shipping with ControlVault-enabled security hardware

Discovery Timeline

2025-06-13 - CVE-2025-25050 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-25050

Vulnerability Analysis

Dell ControlVault3 is a firmware-based security subsystem that runs on a dedicated Unified Security Hub (USH) chip. It stores credentials, biometric templates, and cryptographic material outside the main operating system. The cv_upgrade_sensor_firmware handler processes firmware upgrade requests for peripheral sensors managed through the ControlVault API.

The function fails to properly validate the size or offset of attacker-controlled input before writing to a fixed memory region. A crafted API request supplies parameters that steer the write beyond the intended buffer boundary. The result is memory corruption inside the ControlVault firmware execution context.

Because the write occurs inside privileged firmware, exploitation crosses a trust boundary. The scope change indicates that a compromised low-privilege caller can affect resources managed by a different security authority, including credential material and platform authentication state.

Root Cause

The root cause is insufficient bounds checking on parameters passed to cv_upgrade_sensor_firmware. The handler treats caller-supplied length or index fields as trusted, allowing writes past the allocated buffer. This is a classic [CWE-787] pattern applied to embedded firmware.

Attack Vector

The attack vector is local. An authenticated user with the ability to invoke the ControlVault API on the host operating system can send the malformed request. No user interaction is required. Because ControlVault is reachable from user-mode software on affected Dell systems, any low-privilege process that can open the ControlVault interface is a viable entry point.

Exploitation details are described in the Talos Intelligence Vulnerability Report TALOS-2025-2137 and the Dell Security Advisory DSA-2025-053. No public proof-of-concept exploit code has been released at this time.

Detection Methods for CVE-2025-25050

Indicators of Compromise

Unexpected ControlVault firmware version mismatches or downgrade attempts reported by Dell management tooling
User-mode processes opening handles to ControlVault device interfaces outside of Dell service processes such as BcmBiosMgr and WinBioSrvc
Crashes, hangs, or repeated resets of the ControlVault USH device recorded in Windows Event Log source Broadcom or Dell diagnostic logs

Detection Strategies

Inventory ControlVault3 and ControlVault3 Plus firmware versions across the fleet and flag any host below the fixed versions 5.15.10.14 and 6.2.26.36
Monitor for non-Dell binaries invoking ControlVault APIs, which is atypical on managed endpoints
Correlate local privilege escalation alerts with ControlVault device errors in the same time window

Monitoring Recommendations

Ingest Dell Command | Update and ControlVault diagnostic logs into a central data lake for version and error telemetry
Alert on new or unsigned processes loading Broadcom ControlVault client libraries such as BcmDeviceAndTaskStatusService components
Track kernel driver load events for bcmfnusb.sys and related ControlVault drivers to establish a baseline of legitimate callers

How to Mitigate CVE-2025-25050

Immediate Actions Required

Apply the Dell ControlVault firmware updates published in DSA-2025-053 to all affected endpoints
Prioritize systems where ControlVault is actively used for Windows Hello, fingerprint authentication, or smart card operations
Restrict interactive and remote logon rights on affected hosts to reduce the local attacker population

Patch Information

Dell has released fixed firmware in Dell ControlVault3 version 5.15.10.14 and Dell ControlVault3 Plus version 6.2.26.36. Distribute the update through Dell Command | Update, Dell Client Management Pack, or standard patch management tooling. Verify the ControlVault firmware version after deployment because the fix is delivered as a firmware payload rather than a standard OS package.

Workarounds

Disable ControlVault-dependent features such as fingerprint reader and smart card readers where they are not required, reducing exposure of the vulnerable API surface
Enforce application allowlisting so only signed Dell binaries can call ControlVault interfaces on unpatched hosts
Limit membership in local administrator and interactive logon groups until firmware updates are confirmed installed

bash

# Verify installed ControlVault firmware version on Windows endpoints
# Adjust the WMI class name if Dell tooling exposes it under a different namespace
Get-CimInstance -Namespace root\dcim\sysman -ClassName DCIM_SoftwareIdentity |
  Where-Object { $_.ElementName -like "*ControlVault*" } |
  Select-Object ElementName, VersionString