perl-security

perl-security is a skill for Claude Code from loulanyue/awesome-claude-notes. It costs 43 tokens per session (3,855 once invoked), scanned B, original, MIT.

A set of security guidelines for Perl programs, including safe handling of user input, files, system commands, database queries, and web requests.

In plain words
What is it for?
Use it when writing or reviewing Perl code that handles external input, runs commands, accesses files, connects to databases, or serves web pages.
Why use it?
It helps prevent problems such as code injection, unsafe file access, cross-site scripting, and forged web requests.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: positional $N argument.

Part of the awesome-claude-notes plugin — 106 skills, 61 commands, 28 agents shipped together

Good fit Use it when writing or reviewing Perl code that handles external input, runs commands, accesses files, connects to databases, or serves web pages.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/loulanyue/awesome-claude-notes/perl-security
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add loulanyue/awesome-claude-notes --skill perl-security
Clone the repo
git clone --depth 1 https://github.com/loulanyue/awesome-claude-notes

Made for: Claude Code.

Or install awesome-claude-notes, the plugin that ships this one along with the rest of its 106 skills, 61 commands, 28 agents.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for perl-security

README.md
[![agentmods](https://agentmods.dev/badge/skills/loulanyue/awesome-claude-notes/perl-security/github.svg)](https://agentmods.dev/skills/loulanyue/awesome-claude-notes/perl-security)
Your own site
<a href="https://agentmods.dev/skills/loulanyue/awesome-claude-notes/perl-security"><img src="https://agentmods.dev/badge/skills/loulanyue/awesome-claude-notes/perl-security/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for perl-security

Your own site · 80×15
<a href="https://agentmods.dev/skills/loulanyue/awesome-claude-notes/perl-security"><img src="https://agentmods.dev/badge/skills/loulanyue/awesome-claude-notes/perl-security.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 43 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,855 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 8 findings, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Tool Misuse · line 179
    Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).
    Fix: Validate all tool parameters against an allowlist. Reject dangerous parameter values (shell=True, --force, -rf /) and use safe defaults.
  • high Tool Misuse · line 240
    Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).
    Fix: Validate all tool parameters against an allowlist. Reject dangerous parameter values (shell=True, --force, -rf /) and use safe defaults.
  • high Tool Misuse · line 179
    Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).
    Fix: Validate all tool parameters against an allowlist. Reject dangerous parameter values (shell=True, --force, -rf /) and use safe defaults.
  • high Tool Misuse · line 179
    Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).
    Fix: Validate all tool parameters against an allowlist. Reject dangerous parameter values (shell=True, --force, -rf /) and use safe defaults.
  • high Tool Misuse · line 240
    Tool calls are chained to bypass individual safety checks or escalate capabilities beyond what any single tool call would allow.
    Fix: Limit tool chaining depth and validate the output of each tool before passing it to the next. Require explicit user approval for multi-step chains.
  • high YARA Match · line 240
    YARA rule matched a known malware signature (reverse shell, backdoor, ransomware, C2 framework, or info stealer).
    Fix: Remove the malware payload or compromised file entirely. Investigate how it entered the skill and audit all other artifacts for additional indicators of compromise.
  • medium Agent Snooping · line 4
    Skill enumerates or reads other installed skills. Access to other skills' SKILL.md files or the skills directory reveals prompt instructions, capabilities, and secrets that should be invisible to peer skills.
    Fix: Remove all code or instructions that list or read other skills' files or directories. Skills should operate independently; cross-skill access is a privilege escalation.
  • medium Agent Snooping · line 507
    Skill enumerates or reads other installed skills. Access to other skills' SKILL.md files or the skills directory reveals prompt instructions, capabilities, and secrets that should be invisible to peer skills.
    Fix: Remove all code or instructions that list or read other skills' files or directories. Skills should operate independently; cross-skill access is a privilege escalation.
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00043 $0.03855
Opus 5 $0.00022 $0.01928
Sonnet 5 $0.00009 $0.00771
Haiku 4.5 $0.00004 $0.00385

Measured 7d ago against content hash 9a9cacfcdf07, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade B, and why

perl-security scanned grade B with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Recursive force deletemediumDestructive command

rm -rf with a variable or a broad path is one typo away from removing the wrong tree.

open my $fh, $path; # If $path = "|rm -rf /", runs command!

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

Origin

Copies of this mod

6 near-identical copies found in the catalogue:

docs/ja-JP/skills/perl-security/SKILL.md · 513 lines

How it starts

The opening of the file, as written. The whole thing — 513 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Perl Security Patterns

Comprehensive security guidelines for Perl applications covering input validation, injection prevention, and secure coding practices.

When to Activate

  • Handling user input in Perl applications
  • Building Perl web applications (CGI, Mojolicious, Dancer2, Catalyst)
  • Reviewing Perl code for security vulnerabilities
  • Performing file operations with user-supplied paths
  • Executing system commands from Perl
  • Writing DBI database queries

How It Works

Start with taint-aware input boundaries, then move outward: validate and untaint inputs, keep filesystem and process execution constrained, and use parameterized DBI queries everywhere. The examples below show the safe defaults this skill expects you to apply before shipping Perl code that touches user input, the shell, or the network.

Taint Mode

Perl's taint mode (-T) tracks data from external sources and prevents it from being used in unsafe operations without explicit validation.

Enabling Taint Mode

#!/usr/bin/perl -T
use v5.36;

# Tainted: anything from outside the program
my $input    = $ARGV[0];        # Tainted
my $env_path = $ENV{PATH};      # Tainted
my $form     = <STDIN>;         # Tainted
my $query    = $ENV{QUERY_STRING}; # Tainted

# Sanitize PATH early (required in taint mode)
$ENV{PATH} = '/usr/local/bin:/usr/bin:/bin';
delete @ENV{qw(IFS CDPATH ENV BASH_ENV)};

Untainting Pattern

use v5.36;

# Good: Validate and untaint with a specific regex
sub untaint_username($input) {
    if ($input =~ /^([a-zA-Z0-9_]{3,30})$/) {
        return $1;  # $1 is untainted
    }
    die "Invalid username: must be 3-30 alphanumeric characters\n";
}

# Good: Validate and untaint a file path
sub untaint_filename($input) {
    if ($input =~ m{^([a-zA-Z0-9._-]+)$}) {
        return $1;
    }
    die "Invalid filename: contains unsafe characters\n";
}

# Bad: Overly permissive untainting (defeats the purpose)
sub bad_untaint($input) {
    $input =~ /^(.*)$/s;
    return $1;  # Accepts ANYTHING — pointless
}

Read the full file on GitHub · 513 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 7d ago First seen · 513 lines · 43 tokens per session scan B 9a9cacfcdf07

Subscribe to this mod's changes

perl-security is a skill published in the GitHub repository loulanyue/awesome-claude-notes (270 stars, last pushed 7d ago), licensed MIT. It adds 43 tokens to every session and 3,855 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it B with 1 finding (recursive force delete). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.