T05 · Unauthorized Access and Privilege Escalation
- Location
references/users.md:68- Finding
Unrestricted Passwordless Root Access Through Sudoers Configuration
- Content
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Vulnerability Details
File Location:
references/users.md, line 68
Vulnerability Type: Unrestricted passwordless privilege escalation
Risk Level: HighVulnerable Code:
text username ALL=(ALL) NOPASSWD: ALLTechnical Analysis
The documented sudoers rule grants
usernamepermission to execute every command as any user, including root, without authentication. This violates least-privilege principles and removes the password prompt that would otherwise provide an additional control against unauthorized privilege escalation.Although the Skill is a command-reference document and does not apply this configuration automatically, an agent or administrator following the guidance could introduce a persistent access-control weakness. The reference provides no command restrictions, authentication requirement,
visudovalidation guidance, explicit authorization requirement, or rollback procedure.Attack Path
- An agent or administrator adds the documented rule to the system's sudoers configuration.
- An attacker compromises the
usernameaccount, obtains execution in its session, or exploits an application running under that account. - The attacker invokes an arbitrary command through
sudo, such as starting a root shell. - Because the rule uses
NOPASSWD: ALL, no password or additional authentication is required. - The attacker gains unrestricted root-level control of the host.
Impact Assessment
Successful exploitation grants complete administrative privileges on the affected system. An attacker could read or modify protected data, access credentials, alter security controls, create accounts, install persistent services or scheduled tasks, tamper with logs, and execute arbitrary commands as root.
The impact applies to any host where this example is implemented. The package itself contains no script that automatically installs the rule.
- Remediation
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Remediation Suggestions
- Remove the unrestricted
NOPASSWD: ALLexample. - Grant only the minimum commands required for a defined operational role, using absolute executable paths and narrowly scoped arguments where feasible.
- Retain password authentication unless a documented automation requirement makes passwordless execution unavoidable.
- Place approved rules in a dedicated file under
/etc/sudoers.d/with restrictive ownership and permissions. - Edit and validate sudoers rules using
visudoorvisudo -cfbefore deployment. - Require explicit user authorization before modifying sudo privileges.
- Avoid granting access to interpreters, shells, editors, or commands that can escape into arbitrary command execution.
- Document testing, auditing, expiration, and rollback procedures for every elevated permission.
- Remove the unrestricted