📖 ~1 min read
Table of contents
Symptom & Impact
Privilege escalation fails and routine administration is blocked.
Environment & Reproduction
Seen after manual edits or automation with incorrect file modes.
Root Cause Analysis
sudo rejects insecure ownership or syntax errors in policy includes.
Quick Triage
Use visudo checks and inspect file mode and owner integrity.
Step-by-Step Diagnosis
Validate sudoers and include files with visudo -c and stat.
Solution – Primary Fix
Restore correct ownership and permissions and fix policy syntax.
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Solution – Alternative Approaches
Temporarily recover via root console if sudo path is unavailable.
Verification & Acceptance Criteria
sudo commands execute with expected policy and logging.
Rollback Plan
Restore prior verified sudoers backup if validation fails.
Prevention & Hardening
Apply sudo policy through managed templates and CI lint checks.
Related Errors & Cross-Refs
Related to PAM, NSS, and authentication backend failures.
Related tutorial: View the step-by-step tutorial for debian-9.
View all debian-9 tutorials on the Tutorials Hub →
Browse all common problems & solutions on the Tutorials Hub.
References & Further Reading
sudoers manual and Debian security administration guides.
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