Cron Scheduler

PassAudited by VirusTotal on May 11, 2026.

Overview

Type: OpenClaw Skill Name: openclaw-skill-cron-scheduler Version: 1.0.0 The skill is a standard utility for managing cron jobs on macOS and Linux via the `scripts/cron-helper.sh` bash script. It provides expected functionality such as listing, adding, removing, and backing up crontabs using system-native commands like `crontab`, `systemctl`, and `launchctl`. The script includes safety features such as basic cron expression validation and automatic backups to `~/.cron-backups/`, and shows no evidence of malicious intent, data exfiltration, or unauthorized persistence.

Findings (0)

Artifact-based informational review of SKILL.md, metadata, install specs, static scan signals, and capability signals. ClawScan does not execute the skill or run runtime probes.

ConcernMedium Confidence
ASI05: Unexpected Code Execution
What this means

A malicious or mistaken line-number argument could alter more of the crontab than intended or run unintended sed-supported actions.

Why it was flagged

The remove-by-line value is inserted directly into a sed program instead of being validated as a number; crafted input can change the sed script, and on some sed implementations may trigger behavior beyond simple line deletion.

Skill content
echo "$current_crontab" | sed -n "H;1h;\$!d;x;s/^[0-9]*[ \t]*//;${value}d" > "$temp_file"
Recommendation

Validate line numbers with a strict numeric check and use a safer deletion method, with a preview and confirmation before applying changes.

ConcernHigh Confidence
ASI10: Rogue Agents
What this means

A scheduled command may keep running in the background long after the user or agent interaction ends.

Why it was flagged

The add path writes an arbitrary command into the user's crontab, creating recurring execution that persists after the immediate task.

Skill content
echo "$schedule $command" >> "$temp_file" ... crontab "$temp_file"
Recommendation

Only add cron jobs after reviewing the exact command and schedule; prefer explicit confirmation, labels/comments, and a backup before changes.

ConcernMedium Confidence
ASI02: Tool Misuse and Exploitation
What this means

A mistaken pattern could delete important scheduled jobs and disrupt backups, syncs, monitoring, or other automation.

Why it was flagged

The remove-by-pattern path rewrites the crontab based on a user-supplied pattern; a broad regex can remove multiple jobs, and the shown code does not include a preview or confirmation.

Skill content
echo "$current_crontab" | grep -v "$value" > "$temp_file" ... crontab "$temp_file"
Recommendation

List jobs first, back up manually, and require a preview/confirmation before pattern-based removal.

What this means

Approving sudo prompts can affect system-wide cron behavior, including other scheduled tasks.

Why it was flagged

Service management uses sudo to start or stop the system cron daemon. This is disclosed and purpose-aligned, but it crosses a privilege boundary.

Skill content
sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.cron.plist ... sudo systemctl start cron ... sudo systemctl stop cron
Recommendation

Approve sudo service actions only when you explicitly intend to start or stop the cron daemon.

What this means

You may be less cautious about destructive changes if you assume automatic rollback is guaranteed.

Why it was flagged

The safety claim is not clearly backed by the shown add/remove implementation, where crontab changes are installed directly; users may rely on an automatic backup that is not evident in the provided code excerpt.

Skill content
- Backup created before any destructive operations
Recommendation

Treat backups as manual unless the implementation is updated or verified; run the backup command before add/remove/restore operations.