CVE-2025-45784 Overview
CVE-2025-45784 is a critical hardcoded credentials vulnerability affecting D-Link DPH-400S/SE VoIP phones running firmware version 1.01. The firmware contains hardcoded provisioning variables, including PROVIS_USER_PASSWORD, which exposes sensitive user credentials. An attacker with access to the firmware image can extract these credentials using static analysis tools such as strings or xxd, potentially leading to unauthorized access to device functions or user accounts.
This vulnerability exists due to insecure storage of sensitive information directly within the firmware binary, a common security anti-pattern in embedded devices that violates fundamental secure development practices.
Critical Impact
Hardcoded credentials in firmware allow attackers to extract authentication secrets through static analysis, enabling unauthorized access to VoIP phone administration and potentially compromising voice communications infrastructure.
Affected Products
- D-Link DPH-400SE Firmware v1.01
- D-Link DPH-400SE Hardware
- D-Link DPH-400S Firmware v1.01
- D-Link DPH-400S Hardware
Discovery Timeline
- 2025-06-18 - CVE-2025-45784 published to NVD
- 2025-07-22 - Last updated in NVD database
Technical Details for CVE-2025-45784
Vulnerability Analysis
This vulnerability is classified under CWE-798 (Use of Hard-coded Credentials), a severe security weakness that fundamentally undermines authentication mechanisms. The D-Link DPH-400S/SE VoIP phone firmware version 1.01 embeds provisioning credentials directly into the binary image, making them accessible to anyone who can obtain a copy of the firmware.
The hardcoded PROVIS_USER_PASSWORD variable and other provisioning secrets are stored in plaintext within the firmware binary. This design flaw allows attackers to perform offline credential extraction without requiring any network access to the target device. Once extracted, these credentials can be used across all devices running the same firmware version, as the credentials are not unique per device.
The impact extends beyond individual device compromise—VoIP phones often have access to voice communications, call logs, and network configurations. Compromised credentials could enable eavesdropping, call manipulation, or lateral movement within enterprise networks.
Root Cause
The root cause of this vulnerability is the insecure storage of sensitive provisioning credentials directly within the firmware binary. Rather than implementing secure credential provisioning mechanisms (such as device-specific key generation during initial setup or secure key storage), the developers embedded static credentials that are identical across all devices running this firmware version.
This approach violates the principle of defense in depth and fails to account for the ease with which firmware images can be obtained—either through vendor download portals, physical device access, or network interception during firmware updates.
Attack Vector
The attack vector for CVE-2025-45784 is network-based according to the CVSS vector, though the exploitation methodology involves offline firmware analysis. An attacker can obtain the firmware through several methods:
- Firmware Download: Acquiring the firmware from D-Link's support website or firmware update servers
- Device Extraction: Physically dumping the firmware from flash memory via JTAG, SPI, or UART interfaces
- Network Interception: Capturing firmware during over-the-air updates if transmitted insecurely
Once the firmware is obtained, static analysis tools can extract the hardcoded credentials. The strings command can identify readable ASCII strings, while xxd provides hexadecimal analysis capabilities. Binary analysis frameworks like Binwalk can extract filesystem contents for deeper inspection.
The extracted credentials enable authentication to the device's provisioning interface, potentially granting administrative access to VoIP phone configuration, network settings, and call management functions.
Detection Methods for CVE-2025-45784
Indicators of Compromise
- Unexpected authentication attempts to VoIP phone provisioning interfaces using known hardcoded credentials
- Unauthorized configuration changes on DPH-400S/SE devices without corresponding administrator activity
- Anomalous network traffic to/from VoIP phones suggesting command and control activity
- Evidence of firmware extraction tools or JTAG/SPI debugging equipment usage in proximity to devices
Detection Strategies
- Monitor authentication logs on VoIP phones and associated management systems for successful logins from unauthorized sources
- Implement network traffic analysis to detect unusual communication patterns from D-Link VoIP devices
- Deploy file integrity monitoring on VoIP phone configurations to detect unauthorized modifications
- Utilize firmware analysis tools during security assessments to identify hardcoded credentials before deployment
Monitoring Recommendations
- Enable comprehensive logging on network management systems for all VoIP device authentication events
- Configure SIEM alerts for authentication attempts using known default or hardcoded credential patterns
- Implement network segmentation to isolate VoIP devices and monitor cross-segment traffic anomalies
- Establish baseline behavior profiles for VoIP phones to detect deviations indicating compromise
How to Mitigate CVE-2025-45784
Immediate Actions Required
- Consult the D-Link Security Bulletin for official guidance and firmware updates
- Implement network segmentation to isolate affected DPH-400S/SE devices from critical infrastructure
- Restrict physical access to VoIP phones to prevent firmware extraction via hardware interfaces
- Monitor authentication logs for signs of credential abuse until patches are applied
- Consider deploying additional authentication controls at the network level to restrict access to device management interfaces
Patch Information
Organizations should monitor the D-Link Security Bulletin for official patch releases addressing CVE-2025-45784. Until an official firmware update is available that removes hardcoded credentials, organizations should implement compensating controls to reduce risk exposure.
For additional technical details regarding this vulnerability, refer to the Cyber Maya Blog Post which provides further analysis.
Workarounds
- Implement strict network access controls limiting connectivity to VoIP phone management interfaces to trusted administrator workstations only
- Deploy a network-based Web Application Firewall (WAF) or intrusion prevention system to filter suspicious provisioning requests
- Consider replacing affected devices with VoIP phones from vendors that implement secure credential storage practices
- If device replacement is not feasible, implement additional authentication layers such as VPN requirements for administrative access
- Conduct regular security audits of VoIP infrastructure to detect unauthorized access attempts
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
