CVE-2025-27688 Overview
CVE-2025-27688 is an improper permissions vulnerability affecting Dell ThinOS version 2408 and earlier releases. A low-privileged attacker with local access to an affected thin client can exploit the flaw to elevate privileges on the device. The weakness maps to [CWE-732] Incorrect Permission Assignment for Critical Resource. Dell published advisory DSA-2025-107 to address the issue across ThinOS-powered Latitude, OptiPlex, and Wyse endpoints. The vulnerability requires local access but no user interaction, making it relevant to environments where thin clients are shared across multiple users or shifts.
Critical Impact
A local low-privileged user can escalate privileges on Dell ThinOS thin clients, compromising confidentiality, integrity, and availability of the endpoint.
Affected Products
- Dell ThinOS 2408 and prior
- Dell Latitude 3420, 3440, 5440, 5450
- Dell OptiPlex 3000 Thin Client, 5400/7410/7420 All-in-One, and Wyse 5070/5470 Thin Client models
Discovery Timeline
- 2025-03-18 - CVE-2025-27688 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-27688
Vulnerability Analysis
CVE-2025-27688 stems from incorrect permission assignment on critical resources within Dell ThinOS. ThinOS is a firmware-based operating system that runs on Dell Wyse and thin client hardware to broker access to virtual desktop infrastructure. The flaw allows a local, authenticated user with limited privileges to interact with resources whose permissions grant broader access than intended.
Because thin clients frequently operate in shared kiosk or shift-worker environments, an attacker who obtains standard user access can leverage this misconfiguration to gain elevated rights on the device. Successful exploitation compromises confidentiality, integrity, and availability of the endpoint, per Dell advisory DSA-2025-107.
Root Cause
The root cause is improper permission assignment classified under [CWE-732]. One or more critical resources on ThinOS 2408 and earlier grant access rights that are broader than required for a low-privileged user context. This mismatch enables unauthorized modification or execution paths that should be restricted to administrative users.
Attack Vector
Exploitation requires local access to the thin client and a low-privileged account. No user interaction is required from another user. An attacker with physical or remote-session access to the device targets the improperly permissioned resource and executes actions that yield elevated privileges within the ThinOS environment.
No public proof-of-concept exploit code is available for CVE-2025-27688. Refer to the Dell Security Advisory DSA-2025-107 for vendor-provided technical detail.
Detection Methods for CVE-2025-27688
Indicators of Compromise
- Unexpected privilege changes or administrative actions initiated from standard user sessions on ThinOS devices
- ThinOS configuration modifications outside authorized change windows or management tools such as Wyse Management Suite
- Local logon events on thin clients followed by access to system-level resources that standard users should not reach
Detection Strategies
- Inventory all ThinOS endpoints and confirm firmware version against 2408 and prior to identify vulnerable systems
- Correlate local authentication events on thin clients with subsequent privileged operations to surface anomalous escalation attempts
- Monitor Wyse Management Suite audit logs for unauthorized configuration changes pushed from or applied to endpoints
Monitoring Recommendations
- Forward ThinOS device logs and Wyse Management Suite events to a centralized SIEM for retention and correlation
- Alert on repeated local logon failures followed by successful low-privileged sessions on the same device
- Track firmware version drift across the thin client fleet to detect systems that have not received the DSA-2025-107 fix
How to Mitigate CVE-2025-27688
Immediate Actions Required
- Identify all Dell ThinOS endpoints running version 2408 or earlier and prioritize them for remediation
- Apply the ThinOS update referenced in Dell advisory DSA-2025-107 through Wyse Management Suite or the standard update channel
- Restrict physical and remote local access to thin clients to trusted users until patching is complete
Patch Information
Dell has published remediation guidance in Dell Security Advisory DSA-2025-107. Administrators should follow the vendor-specified upgrade path to a fixed ThinOS release for each affected Latitude, OptiPlex, and Wyse platform listed in the advisory.
Workarounds
- Enforce strong local account policies and disable unused local user accounts on ThinOS devices
- Limit interactive access to thin clients to authenticated corporate users through Wyse Management Suite policy
- Physically secure thin clients deployed in shared or public-facing locations to reduce opportunistic local access
# Verify ThinOS firmware version and target vulnerable endpoints via Wyse Management Suite
# Example (conceptual) query — replace with your WMS API endpoint and token
curl -H "Authorization: Bearer $WMS_TOKEN" \
"https://wms.example.com/api/v1/devices?os=ThinOS&versionLte=2408"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
