CVE-2025-54756 Overview
BrightSign players running BrightSign OS series 4 prior to v8.5.53.1 or series 5 prior to v9.0.166 contain a default password vulnerability where the password is guessable with knowledge of the device information. This weakness (CWE-1392: Use of Default Credentials) allows attackers with local access to potentially gain unauthorized access to affected digital signage players. The latest release fixes this issue for new installations; however, users of existing installations are encouraged to change all default passwords immediately.
Critical Impact
Attackers with local access and knowledge of device information can guess the default password, potentially gaining full control over BrightSign digital signage players and the content they display.
Affected Products
- BrightSign OS series 4 prior to version 8.5.53.1
- BrightSign OS series 5 prior to version 9.0.166
- BrightSign digital signage players running vulnerable firmware versions
Discovery Timeline
- 2026-02-12 - CVE CVE-2025-54756 published to NVD
- 2026-02-12 - Last updated in NVD database
Technical Details for CVE-2025-54756
Vulnerability Analysis
This vulnerability stems from the use of default credentials that can be derived from device-specific information. BrightSign digital signage players are deployed in various commercial environments including retail stores, airports, corporate lobbies, and public spaces. The default password implementation uses a predictable algorithm that incorporates device information, making it possible for an attacker to determine the password if they have access to device details such as serial numbers or other identifying characteristics.
The local attack vector requires physical proximity to the device, but given the public deployment nature of digital signage players, this represents a significant security concern. Once an attacker gains access, they could potentially modify displayed content, use the device as a pivot point for network attacks, or disrupt business operations.
Root Cause
The root cause is classified under CWE-1392 (Use of Default Credentials). The BrightSign OS firmware uses a default password generation scheme that incorporates predictable device information. This design flaw means that anyone with knowledge of the device's identifying information can potentially calculate or guess the default password, bypassing authentication entirely.
Attack Vector
The attack requires local access to the BrightSign player. An attacker would need to:
- Gain physical proximity to a BrightSign digital signage player
- Obtain device information (such as serial number or model details, often visible on the device or through network enumeration)
- Use this information to derive the default password
- Authenticate to the device using the guessed credentials
- Gain unauthorized access to device configuration and content management
Given that digital signage players are often deployed in public or semi-public areas with minimal physical security, this attack vector is practical for determined adversaries. The vulnerability does not require user interaction, and the attack complexity is low once the device information is obtained.
Detection Methods for CVE-2025-54756
Indicators of Compromise
- Unexpected changes to digital signage content or configurations
- Unauthorized login attempts or successful authentications in device logs
- Modification of network settings or scheduled content on BrightSign players
- Unusual network traffic originating from digital signage devices
Detection Strategies
- Monitor authentication logs on BrightSign players for unusual access patterns
- Implement network monitoring to detect unauthorized management traffic to signage devices
- Conduct regular audits of BrightSign device configurations to identify unauthorized changes
- Deploy network segmentation monitoring to detect lateral movement from compromised signage players
Monitoring Recommendations
- Enable logging on all BrightSign devices and centralize log collection
- Set up alerts for configuration changes made outside of approved maintenance windows
- Monitor for devices still running firmware versions prior to 8.5.53.1 (series 4) or 9.0.166 (series 5)
- Implement physical security monitoring for devices deployed in public areas
How to Mitigate CVE-2025-54756
Immediate Actions Required
- Change all default passwords on existing BrightSign installations immediately
- Update BrightSign OS series 4 devices to version 8.5.53.1 or later
- Update BrightSign OS series 5 devices to version 9.0.166 or later
- Audit all deployed BrightSign players to identify vulnerable firmware versions
- Implement strong, unique passwords for each device
Patch Information
BrightSign has released updated firmware that addresses this vulnerability for new installations. The patched versions are:
- Series 4: Version 8.5.53.1 and later
- Series 5: Version 9.0.166 and later
Updated firmware can be downloaded from the BrightSign Software Downloads page. Users should note that while the updated firmware fixes the issue for new installations, existing installations require manual password changes. For additional technical details, refer to the CISA ICS Advisory.
Workarounds
- Immediately change default passwords on all BrightSign devices to strong, unique passwords
- Implement network segmentation to isolate digital signage players from critical network infrastructure
- Restrict physical access to BrightSign devices where possible
- Disable remote management interfaces if not required for operations
- Apply firmware updates during the next available maintenance window if immediate patching is not feasible
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
