Summary
LTSecurity LTK3500SF stores root and guest account password hashes in a form that can be recovered through dictionary-based cracking. An attacker who obtains the hashes and can reach an enabled Telnet or SSH service may authenticate with the recovered credentials and gain root-level operating-system access.
Affected context
The vulnerability occurs in LTK3500SF devices where privileged account credentials are embedded in or exposed through the device filesystem, including /etc/shadow, and protected only by crackable password representations. Risk increases when Telnet or SSH is enabled and reachable from an attacker-controlled network, or when an attacker can obtain a filesystem image, backup, or other copy containing the credential data.
Exploit preconditions
- Attack surface: Network-accessible Telnet or SSH services, or access to a device filesystem or firmware image
- Required access: Ability to obtain the stored credential hashes and sufficient network reachability to attempt authentication
- Trigger point: Successful authentication using a recovered root or guest password
- Why exploitation is possible: Credential material is embedded in the device and can be recovered with dictionary-based cracking, while remote services accept the affected account credentials
Why this happens
The underlying flaw is the use of embedded, reusable account credentials whose password representations can be recovered through practical cracking techniques. This maps to CWE-798: Use of Hard-coded Credentials, because authentication depends on credential data distributed with the device rather than unique, securely managed credentials. Exposing privileged account hashes and permitting their use over administrative services creates a persistent trust relationship that is difficult to revoke across deployed devices.
Potential impact
- An attacker may authenticate as root or another affected account
- The attacker could modify operating-system files and device configuration
- Device traffic, services, or stored information may be monitored or altered
- The device could be used for lateral movement or as part of a botnet
- Service availability may be disrupted through destructive changes
General mitigation guidance
Mitigation generally focuses on eliminating shared embedded credentials and reducing the value of any credential material that may be exposed.
Common defensive patterns include:
- Provisioning unique, randomly generated credentials for each device
- Requiring credential rotation or enrollment during initial setup
- Replacing password-based administrative access with strong device-bound keys or certificates where practical
- Disabling Telnet and restricting SSH to trusted management networks
- Applying least privilege and preventing routine remote administration with root accounts
- Protecting filesystem images, backups, and credential stores with appropriate access controls
- Using slow, salted password-hashing schemes and avoiding reversible or readily crackable representations
How teams detect issues like this
Organizations can identify similar weaknesses through:
- Static analysis and firmware reviews for embedded usernames, passwords, password hashes, or default-credential generation logic
- Code review signals involving root accounts, fixed authentication data, and unrestricted Telnet or SSH enablement
- Configuration and policy checks that flag administrative services exposed beyond designated management networks
- Credential audits using authorized password-strength and uniqueness testing
- Automated firmware scanning and secret-detection tools used as neutral review aids
