T09 · Insecure Skill Coding Practices
- Location
SKILL.md:112- Finding
Unsafe Benchmarking and System-Tuning Commands May Cause Data Loss or Service Disruption
- Content
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Vulnerability Details
File Location:
SKILL.md, lines 112-119, 334-373, and 517-520
Vulnerability Type:T09: Insecure Skill Coding Practices
Risk Level: MediumVulnerable Code
bash dd if=/dev/zero of=testfile bs=1M count=1000 oflag=direct dd if=testfile of=/dev/null bs=1M count=1000 iflag=direct fio --name=randread --filename=test --rw=randread --bs=4k --iodepth=64 --size=1G --numjobs=4 --runtime=60 --group_reportingbash echo "performance" | sudo tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor echo "powersave" | sudo tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor echo 3 | sudo tee /proc/sys/vm/drop_caches echo noop | sudo tee /sys/block/sda/queue/scheduler echo 0 | sudo tee /sys/block/sda/queue/read_ahead_kb sysctl -w net.core.rmem_max=134217728 sysctl -w net.core.wmem_max=134217728bash sudo hdparm -tT /dev/sda fio --name=seqwrite --filename=test --rw=write --bs=1M --size=1G --numjobs=1 --time_based --runtime=60Technical Analysis
The Skill presents directly executable disk benchmarking and privileged system-tuning commands without requiring target validation, free-space checks, backups, explicit user confirmation, or rollback procedures.
The
ddandfioexamples use predictable generic paths such astestfileandtest. These commands can overwrite existing files in the current directory and consume at least 1 GB of storage. The write benchmark may also impose substantial I/O load and adversely affect other workloads.The tuning examples modify live kernel and hardware-related settings. Clearing filesystem caches can temporarily degrade system performance, while changing CPU governors, network buffers, block-device schedulers, and read-ahead settings can disrupt workloads or be unsuitable for the actual hardware. The hard-coded
/dev/sdatarget assumes a specific device layout without verifying that it is the intended disk ...[truncated 1887 chars]- Remediation
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Remediation Suggestions
- Default to read-only diagnostics and provide mutating optimization commands only after explicit user approval.
- Require confirmation immediately before every privileged command or benchmark that writes data.
- Create benchmark files in a newly generated private temporary directory, using exclusive creation to prevent overwrites and link-based attacks.
- Check available disk capacity and filesystem quotas before allocating benchmark files.
- Verify the selected block device through
lsblk, mount information, and stable device identifiers instead of assuming/dev/sda. - Warn users about benchmark duration, expected disk usage, I/O load, and possible effects on active services.
- Record existing kernel and device settings before modification and provide tested rollback commands.
- Avoid applying generic scheduler or read-ahead values without detecting the kernel, storage type, and supported settings.
- Clean up benchmark artifacts reliably after completion, including interrupted runs.
- Document that scheduled health reporting and external email or Slack notifications require explicit consent and disclosure of the transmitted report contents and destination.