T09 · Insecure Skill Coding Practices
- Location
scripts/script.sh:5- Finding
Sensitive Payroll Records Are Stored Without Enforced Restrictive Permissions
- Content
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Vulnerability Details
File Location:
scripts/script.sh:5-8, with sensitive-data writes represented atscripts/script.sh:130-136
Vulnerability Type: Insecure local storage permissions for sensitive financial data
Risk Level: MediumVulnerable Code
bash DATA_DIR="${HOME}/.local/share/paycheck" mkdir -p "$DATA_DIR" _log() { echo "$(date '+%m-%d %H:%M') $1: $2" >> "$DATA_DIR/history.log"; }A representative sensitive-data write is:
bash local input="$*" local ts=$(date '+%Y-%m-%d %H:%M') echo "$ts|$input" >> "$DATA_DIR/run.log" local total=$(wc -l < "$DATA_DIR/run.log") echo " [Paycheck] run: $input" echo " Saved. Total run entries: $total" _log "run" "$input"The same storage pattern is repeated by the other recording commands.
Technical Analysis
The application is intended to record salary, tax, insurance, deduction, and other payroll-related information. It creates its data directory and log files without explicitly enforcing access modes. Consequently, permissions are inherited from the invoking process's
umask.Under a permissive
umask, the directory may be accessible to other local users and the generated log files may be readable beyond the owning account. Sensitive input is also written twice: once to the command-specific log and once tohistory.log. This duplication expands the number of files from which payroll information can be disclosed.This is an insecure coding practice rather than a privilege-escalation primitive. Exploitation requires local filesystem access and sufficiently permissive effective permissions. The code does not itself grant elevated privileges.
Attack Path
- A user runs a recording command and supplies sensitive payroll information, such as salary, tax withholding, insurance, or deduction details.
- The script creates
~/.local/share/paycheckand its log files using permissions determined solely by the user's curr ...[truncated 919 chars]
- Remediation
View remediation
Remediation Suggestions
-
Set a restrictive
umaskbefore creating any data directories or files:bash umask 077 -
Create and validate the data directory with owner-only permissions:
bash DATA_DIR="${HOME}/.local/share/paycheck" mkdir -p -m 700 "$DATA_DIR" chmod 700 "$DATA_DIR" -
Ensure every log and export file is owner-readable and owner-writable only. Files can be initialized explicitly before use:
bash touch "$DATA_DIR/history.log" chmod 600 "$DATA_DIR/history.log"Apply mode
600to command logs and generated export files as well. -
Check that the data directory is owned by the current user and reject symlinks or unexpected file types before writing. This reduces the risk of writing through attacker-prepared filesystem objects in environments where the home directory is not fully trusted.
-
Avoid unnecessary duplication of sensitive values in
history.log, or record only non-sensitive metadata such as the command name and timestamp. -
Clearly document that payroll details are persisted in plaintext and provide a deletion or retention mechanism. If the threat model includes compromise of the user's account or storage device, consider authenticated encryption using a securely managed key.
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