CVE-2026-25107 Overview
CVE-2026-25107 affects ELECOM wireless LAN access point devices that use a hard-coded cryptographic key when generating configuration backup files. An attacker who knows the embedded encryption key can decrypt, modify, and re-encrypt the configuration backup. A victim administrator may then be tricked into importing the crafted configuration file, altering device settings without authorization. The weakness is classified under CWE-321: Use of Hard-coded Cryptographic Key. The flaw requires user interaction, since an administrator must restore the malicious backup, but no authentication is needed to craft it.
Critical Impact
Knowledge of the hard-coded key allows attackers to forge encrypted configuration backups that, once restored by an administrator, can tamper with the integrity of ELECOM wireless LAN access point settings.
Affected Products
- ELECOM wireless LAN access point devices (multiple models — refer to vendor advisory)
- See the Elecom Security News Announcement for the complete affected model list
- See JVN #03037325 Advisory for coordinated disclosure details
Discovery Timeline
- 2026-05-13 - CVE-2026-25107 published to NVD
- 2026-05-13 - Last updated in NVD database
Technical Details for CVE-2026-25107
Vulnerability Analysis
The vulnerability stems from the use of a hard-coded cryptographic key embedded in the firmware of ELECOM wireless LAN access points. When an administrator generates a configuration backup, the device encrypts the file using this static key. Because the key is identical across all affected devices and shipped with the firmware, anyone who extracts or learns the key can decrypt any backup produced by these products.
After decryption, an attacker can modify configuration entries such as administrator credentials, DNS settings, routing rules, or wireless parameters. The attacker then re-encrypts the file with the same hard-coded key and delivers it to a target administrator through phishing or social engineering. When the administrator restores the file, the device accepts it as a legitimate backup and applies the malicious settings.
Root Cause
The root cause is the storage of a static cryptographic key within the device firmware rather than deriving a unique key per device or per backup. This design pattern, captured by CWE-321, removes the confidentiality and integrity guarantees that backup encryption is supposed to provide. The encryption becomes obfuscation rather than a security control.
Attack Vector
The attack is network-adjacent in delivery but relies on administrator interaction. An attacker extracts the hard-coded key from publicly obtainable firmware images, builds a tampered configuration file, and tricks an administrator into restoring it. No prior authentication to the device is required. The impact concentrates on integrity, since the attacker controls configuration content rather than reading device data directly.
No verified proof-of-concept code is published. Technical details are coordinated through the JVN #03037325 Advisory.
Detection Methods for CVE-2026-25107
Indicators of Compromise
- Configuration backup files received from untrusted email senders, file-sharing links, or support impersonation messages directed at network administrators.
- Unexpected changes to administrator accounts, DNS resolvers, DHCP options, or wireless SSID settings on ELECOM access points following a recent restore operation.
- Device administration log entries showing a configuration restore action without a corresponding change-management record.
Detection Strategies
- Compare current device configuration against a known-good baseline at regular intervals and alert on drift in security-relevant fields.
- Monitor administrator endpoints for downloads of .bin, .cfg, or vendor-specific backup files originating from email or external messaging platforms.
- Inspect web management traffic on the LAN for configuration import (restore) requests outside scheduled maintenance windows.
Monitoring Recommendations
- Forward access point syslog and administrative event logs to a centralized log platform for retention and correlation.
- Alert on DNS configuration changes on ELECOM devices, since redirecting DNS is a common follow-on objective after configuration tampering.
- Track outbound connections from access points to unfamiliar destinations, which may indicate a planted management or update server.
How to Mitigate CVE-2026-25107
Immediate Actions Required
- Apply firmware updates published by ELECOM as listed in the Elecom Security News Announcement.
- Treat any configuration backup file received from an external source as untrusted and do not restore it.
- Re-generate configuration backups after patching and store them only in access-controlled locations.
- Rotate administrator credentials and pre-shared keys on devices that may have had configurations exposed.
Patch Information
ELECOM has published firmware updates and customer guidance through the Elecom Security News Announcement. Coordinated disclosure details are available in JVN #03037325. Administrators should consult the vendor advisory to identify the specific firmware version that addresses CVE-2026-25107 for each affected model.
Workarounds
- Restrict administrative access to access points to a dedicated management VLAN reachable only by authorized workstations.
- Require out-of-band verification (for example, a phone call or signed ticket) before any administrator imports a configuration backup.
- Disable remote management interfaces on the WAN side until firmware updates are applied.
# Configuration example: restrict management plane to a trusted subnet
# (illustrative ACL applied on an upstream router or firewall)
access-list MGMT_AP permit ip 10.10.20.0 0.0.0.255 host <AP_MGMT_IP> eq 443
access-list MGMT_AP deny ip any host <AP_MGMT_IP>
access-list MGMT_AP permit ip any any
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
