Privilege Escalation via Writable Bash Script Executed by Root Cron Job

📰 Medium · Cybersecurity

Learn how to exploit a writable bash script executed by a root cron job to gain elevated access in Linux, and understand the importance of securing cron jobs and bash scripts.

intermediate Published 20 Jun 2026

Action Steps

Identify writable bash scripts executed by root cron jobs using the command 'crontab -l' and 'ls -l' to check file permissions.
Exploit a writable bash script by injecting malicious code to gain elevated access.
Use the 'cron' utility to schedule a job that executes the malicious script.
Test the exploit in a controlled lab environment to understand the attack vector.
Implement security measures to prevent such exploits, such as restricting file permissions and monitoring cron jobs.

Who Needs to Know This

This article is relevant to cybersecurity professionals, particularly those responsible for securing Linux systems and hardening them against privilege escalation attacks. It can also benefit system administrators and developers who work with cron jobs and bash scripts.

Key Insight

💡 Writable bash scripts executed by root cron jobs can be exploited to gain elevated access in Linux, highlighting the importance of securing cron jobs and bash scripts.

Key Takeaways

Learn how to exploit a writable bash script executed by a root cron job to gain elevated access in Linux, and understand the importance of securing cron jobs and bash scripts.

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Title: Privilege Escalation via Writable Bash Script Executed by Root Cron Job

URL Source: https://medium.com/@kiptryin/privilege-escalation-via-writable-bash-script-executed-by-root-cron-job-e2d607052d16?source=rss------cybersecurity-5

Published Time: 2026-06-20T20:32:51Z

Markdown Content:
# Privilege Escalation via Writable Bash Script Executed by Root Cron Job | by Kiptryin | Jun, 2026 | Medium

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# Privilege Escalation via Writable Bash Script Executed by Root Cron Job

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**DISCLAIMER**: The techniques demonstrated in this write-up are intended solely for educational purposes. Please ensure that any testing is conducted only within your own controlled lab environment or on systems for which you have explicit, written authorization. Unauthorized access or testing is illegal and unethical.

**What is cronjob?**

Cronjob is a scheduled job in unix-like systems. The cron utility is a time-based job scheduler for Unix-like operating systems. Adversaries may abuse the cron utility to perform task scheduling for initial or recurring execution of malicious code.

**Exploiting a scheduled writeable bash script to gain elevated access in linux**

In our lab we are going to exploit a writeable bash in ubuntu to gain

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Privilege Escalation via Writable Bash Script Executed by Root Cron Job

Key Takeaways

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