Modify Authentication Process: Network Device Authentication
- ID
- T1556.004
- Tactics
- TA0003 Persistence, TA0006 Credential Access, TA0112 Defense Impairment
- Sub-technique of
- T1556 Modify Authentication Process
- Platforms
- Network Devices
- Data sources
- File Modification, User Account Authentication
- Source
- attack.mitre.org
- MITRE last modified
- 12 May 2026
Adversaries may use Patch System Image to hard code a password in the operating system, thus bypassing of native authentication mechanisms for local accounts on network devices.
Modify System Image may include implanted code to the operating system for network devices to provide access for adversaries using a specific password. The modification includes a specific password which is implanted in the operating system image via the patch. Upon authentication attempts, the inserted code will first check to see if the user input is the password. If so, access is granted. Otherwise, the implanted code will pass the credentials on for verification of potentially valid credentials.[2]
Detection
- DET0272 Detect Modification of Network Device Authentication via Patched System Images
Data components: File Modification, User Account Authentication
Mitigations (2)
- M1026 Privileged Account Management
Restrict administrator accounts to as few individuals as possible, following least privilege principles. Prevent credential overlap across systems of administrator and privileged accounts, particularly between network and non-network platforms, such as servers or endpoints.
- M1032 Multi-factor Authentication
Use multi-factor authentication for user and privileged accounts. Most embedded network devices support TACACS+ and/or RADIUS. Follow vendor prescribed best practices for hardening access control. [1]
Software (3)
References
- Cisco IOS Software Integrity Assurance - TACACS
- Mandiant - Synful Knock