Detectors Reference

DetectorsConfig

type DetectorsConfig = {
  prototypePollution?: boolean;
  commandInjection?: boolean;
  pathTraversal?: boolean | PathTraversalOptions;
  redos?: boolean | RedosOptions;
  ssrf?: boolean | SsrfOptions;
  unsafeEval?: boolean;
};

Set to true to enable with defaults, false to disable, or an options object to enable with custom configuration.

Tier 1 (Enabled by Default)

commandInjection

Detects attacker-controlled strings reaching shell execution functions.

How it works: Hooks all child_process module functions (exec, execSync, spawn, spawnSync, fork, execFile, execFileSync). Checks if the goal string vitiate_cmd_inject appears in the command or arguments.

Tokens contributed: vitiate_cmd_inject, shell metacharacters (;, |, `, $(), etc.)

Options: None

pathTraversal

Detects file system access outside allowed directories.

How it works: Hooks fs and fs/promises functions (readFile, readFileSync, writeFile, writeFileSync, mkdir, mkdirSync, unlink, unlinkSync, stat, statSync, access, accessSync, readdir, readdirSync, open, openSync, rename, renameSync). Resolves paths and checks against deny/allow lists.

Tokens contributed: ../, ../../, ../../../, %2e%2e, %2f, null byte, /etc/passwd, /etc/shadow

Options:

interface PathTraversalOptions {
  allowedPaths?: string[];  // Allowed path prefixes
  deniedPaths?: string[];   // Denied paths (checked before allowed)
}

Evaluation order: denied paths are checked first, then allowed paths, then default deny.

Platform note: Tier 2 (disabled by default) on Windows. Case-insensitive filesystem matching and cross-drive path resolution (e.g., D:\ vs \\?\) make the default deny policy prone to false positives.

unsafeEval

Detects attacker-controlled strings evaluated as code.

How it works: Hooks eval(), Function constructor, setTimeout and setInterval with string arguments. Checks if the goal string vitiate_eval_inject appears in the evaluated code.

Tokens contributed: vitiate_eval_inject, require(, process.exit(, import(

Options: None

Tier 2 (Disabled by Default)

prototypePollution

Detects modifications to built-in JavaScript prototypes.

How it works: Snapshots all built-in prototypes (Object, Array, String, Number, Boolean, Function, RegExp, Date, Map, Set, WeakMap, WeakSet, Promise, Error, ArrayBuffer, Int8Array, Uint8Array, Int16Array, Uint16Array, Int32Array, Uint32Array, Float32Array, Float64Array, BigInt64Array, BigUint64Array, and subtypes) before each fuzzing iteration. After execution, diffs property descriptors to detect additions, modifications, or deletions.

Tokens contributed: __proto__, constructor, prototype, __defineGetter__, __defineSetter__, __lookupGetter__, __lookupSetter__

Options: None

redos

Detects regular expressions with excessive execution time.

How it works: Hooks RegExp.prototype methods (exec, test) and String.prototype methods (match, split, replace, replaceAll, search, matchAll). Measures wall-clock time per call.

Tokens contributed: Repetition patterns (aaaa...!, a]a]a]...!, tab/space sequences)

Options:

interface RedosOptions {
  thresholdMs?: number;  // Maximum allowed time per regex call (default: 100)
}

ssrf

Detects HTTP requests to internal or private network addresses.

How it works: Hooks http.request, https.request, and fetch. Checks request targets against a built-in blocklist of private addresses and configurable host lists.

Built-in blocklist: 127.0.0.0/8, 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16, 169.254.0.0/16, ::1, localhost, metadata.google.internal, 169.254.169.254

Tokens contributed: 127.0.0.1, localhost, 169.254.169.254, 10.0.0.1, metadata.google.internal, http://, https://

Options:

interface SsrfOptions {
  blockedHosts?: string[];  // Additional hosts/CIDRs to block
  allowedHosts?: string[];  // Hosts to allow (overrides blocklist)
}

CLI Detector Syntax

# Enable specific detectors (all defaults off)
-detectors prototypePollution,commandInjection

# With options (dot notation, colon-separated values)
-detectors pathTraversal.deniedPaths=/etc/passwd:/etc/shadow
-detectors ssrf.blockedHosts=10.0.0.0/8:172.16.0.0/12
-detectors redos.thresholdMs=200