fix(hooks): scrub secrets and harden hook security (#348)

* fix(hooks): scrub secrets and harden hook security

- Scrub common secret patterns (api_key, token, password, etc.) from
  observation logs before persisting to JSONL (observe.sh)
- Auto-purge observation files older than 30 days (observe.sh)
- Strip embedded credentials from git remote URLs before saving to
  projects.json (detect-project.sh)
- Add command prefix allowlist to runCommand — only git, node, npx,
  which, where are permitted (utils.js)
- Sanitize CLAUDE_SESSION_ID in temp file paths to prevent path
  traversal (suggest-compact.js)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix(hooks): address review feedback from CodeRabbit and Cubic

- Reject shell command-chaining operators (;|&`) in runCommand, strip
  quoted sections before checking to avoid false positives (utils.js)
- Remove command string from blocked error message to avoid leaking
  secrets (utils.js)
- Fix Python regex quoting: switch outer shell string from double to
  single quotes so regex compiles correctly (observe.sh)
- Add optional auth scheme match (Bearer, Basic) to secret scrubber
  regex (observe.sh)
- Scope auto-purge to current project dir and match only archived
  files (observations-*.jsonl), not live queue (observe.sh)
- Add second fallback after session ID sanitization to prevent empty
  string (suggest-compact.js)
- Preserve backward compatibility when credential stripping changes
  project hash — detect and migrate legacy directories
  (detect-project.sh)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix(hooks): block $() substitution, fix Bearer redaction, add security tests

- Add $ and \n to blocked shell metacharacters in runCommand to prevent
  command substitution via $(cmd) and newline injection (utils.js)
- Make auth scheme group capturing so Bearer/Basic is preserved in
  redacted output instead of being silently dropped (observe.sh)
- Add 10 unit tests covering runCommand allowlist blocking (rm, curl,
  bash prefixes) and metacharacter rejection (;|&`$ chaining), plus
  error message leak prevention (utils.test.js)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix(hooks): scrub parse-error fallback, strengthen security tests

Address remaining reviewer feedback from CodeRabbit and Cubic:

- Scrub secrets in observe.sh parse-error fallback path (was writing
  raw unsanitized input to observations file)
- Remove redundant re.IGNORECASE flag ((?i) inline flag already set)
- Add inline comment documenting quote-stripping limitation trade-off
- Fix misleading test name for error-output test
- Add 5 new security tests: single-quote passthrough, mixed
  quoted+unquoted metacharacters, prefix boundary (no trailing space),
  npx acceptance, and newline injection
- Improve existing quoted-metacharacter test to actually exercise
  quote-stripping logic

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix(security): block $() and backtick inside quotes in runCommand

Shell evaluates $() and backticks inside double quotes, so checking
only the unquoted portion was insufficient. Now $ and ` are rejected
anywhere in the command string, while ; | & remain quote-aware.

Addresses CodeRabbit and Cubic review feedback on PR #348.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
jtzingsheim1
2026-03-08 08:47:31 +10:00
committed by GitHub
parent 03b3e0d0da
commit 9661a6f042
5 changed files with 193 additions and 22 deletions

View File

@@ -25,7 +25,7 @@ async function main() {
// Track tool call count (increment in a temp file)
// Use a session-specific counter file based on session ID from environment
// or parent PID as fallback
const sessionId = process.env.CLAUDE_SESSION_ID || 'default';
const sessionId = (process.env.CLAUDE_SESSION_ID || 'default').replace(/[^a-zA-Z0-9_-]/g, '') || 'default';
const counterFile = path.join(getTempDir(), `claude-tool-count-${sessionId}`);
const rawThreshold = parseInt(process.env.COMPACT_THRESHOLD || '50', 10);
const threshold = Number.isFinite(rawThreshold) && rawThreshold > 0 && rawThreshold <= 10000

View File

@@ -339,6 +339,20 @@ function commandExists(cmd) {
* @param {object} options - execSync options
*/
function runCommand(cmd, options = {}) {
// Allowlist: only permit known-safe command prefixes
const allowedPrefixes = ['git ', 'node ', 'npx ', 'which ', 'where '];
if (!allowedPrefixes.some(prefix => cmd.startsWith(prefix))) {
return { success: false, output: 'runCommand blocked: unrecognized command prefix' };
}
// Reject shell metacharacters. $() and backticks are evaluated inside
// double quotes, so block $ and ` anywhere in cmd. Other operators
// (;|&) are literal inside quotes, so only check unquoted portions.
const unquoted = cmd.replace(/"[^"]*"/g, '').replace(/'[^']*'/g, '');
if (/[;|&\n]/.test(unquoted) || /[`$]/.test(cmd)) {
return { success: false, output: 'runCommand blocked: shell metacharacters not allowed' };
}
try {
const result = execSync(cmd, {
encoding: 'utf8',

View File

@@ -72,6 +72,13 @@ if [ -f "$CONFIG_DIR/disabled" ]; then
exit 0
fi
# Auto-purge observation files older than 30 days (runs once per session)
PURGE_MARKER="${PROJECT_DIR}/.last-purge"
if [ ! -f "$PURGE_MARKER" ] || [ "$(find "$PURGE_MARKER" -mtime +1 2>/dev/null)" ]; then
find "${PROJECT_DIR}" -name "observations-*.jsonl" -mtime +30 -delete 2>/dev/null || true
touch "$PURGE_MARKER" 2>/dev/null || true
fi
# Parse using python via stdin pipe (safe for all JSON payloads)
# Pass HOOK_PHASE via env var since Claude Code does not include hook type in stdin JSON
PARSED=$(echo "$INPUT_JSON" | HOOK_PHASE="$HOOK_PHASE" python3 -c '
@@ -125,14 +132,23 @@ except Exception as e:
PARSED_OK=$(echo "$PARSED" | python3 -c "import json,sys; print(json.load(sys.stdin).get('parsed', False))" 2>/dev/null || echo "False")
if [ "$PARSED_OK" != "True" ]; then
# Fallback: log raw input for debugging
# Fallback: log raw input for debugging (scrub secrets before persisting)
timestamp=$(date -u +"%Y-%m-%dT%H:%M:%SZ")
export TIMESTAMP="$timestamp"
echo "$INPUT_JSON" | python3 -c "
import json, sys, os
echo "$INPUT_JSON" | python3 -c '
import json, sys, os, re
_SECRET_RE = re.compile(
r"(?i)(api[_-]?key|token|secret|password|authorization|credentials?|auth)"
r"""(["'"'"'\s:=]+)"""
r"([A-Za-z]+\s+)?"
r"([A-Za-z0-9_\-/.+=]{8,})"
)
raw = sys.stdin.read()[:2000]
print(json.dumps({'timestamp': os.environ['TIMESTAMP'], 'event': 'parse_error', 'raw': raw}))
" >> "$OBSERVATIONS_FILE"
raw = _SECRET_RE.sub(lambda m: m.group(1) + m.group(2) + (m.group(3) or "") + "[REDACTED]", raw)
print(json.dumps({"timestamp": os.environ["TIMESTAMP"], "event": "parse_error", "raw": raw}))
' >> "$OBSERVATIONS_FILE"
exit 0
fi
@@ -147,32 +163,47 @@ if [ -f "$OBSERVATIONS_FILE" ]; then
fi
# Build and write observation (now includes project context)
# Scrub common secret patterns from tool I/O before persisting
timestamp=$(date -u +"%Y-%m-%dT%H:%M:%SZ")
export PROJECT_ID_ENV="$PROJECT_ID"
export PROJECT_NAME_ENV="$PROJECT_NAME"
export TIMESTAMP="$timestamp"
echo "$PARSED" | python3 -c "
import json, sys, os
echo "$PARSED" | python3 -c '
import json, sys, os, re
parsed = json.load(sys.stdin)
observation = {
'timestamp': os.environ['TIMESTAMP'],
'event': parsed['event'],
'tool': parsed['tool'],
'session': parsed['session'],
'project_id': os.environ.get('PROJECT_ID_ENV', 'global'),
'project_name': os.environ.get('PROJECT_NAME_ENV', 'global')
"timestamp": os.environ["TIMESTAMP"],
"event": parsed["event"],
"tool": parsed["tool"],
"session": parsed["session"],
"project_id": os.environ.get("PROJECT_ID_ENV", "global"),
"project_name": os.environ.get("PROJECT_NAME_ENV", "global")
}
if parsed['input']:
observation['input'] = parsed['input']
if parsed['output'] is not None:
observation['output'] = parsed['output']
# Scrub secrets: match common key=value, key: value, and key"value patterns
# Includes optional auth scheme (e.g., "Bearer", "Basic") before token
_SECRET_RE = re.compile(
r"(?i)(api[_-]?key|token|secret|password|authorization|credentials?|auth)"
r"""(["'"'"'\s:=]+)"""
r"([A-Za-z]+\s+)?"
r"([A-Za-z0-9_\-/.+=]{8,})"
)
def scrub(val):
if val is None:
return None
return _SECRET_RE.sub(lambda m: m.group(1) + m.group(2) + (m.group(3) or "") + "[REDACTED]", str(val))
if parsed["input"]:
observation["input"] = scrub(parsed["input"])
if parsed["output"] is not None:
observation["output"] = scrub(parsed["output"])
print(json.dumps(observation))
" >> "$OBSERVATIONS_FILE"
' >> "$OBSERVATIONS_FILE"
# Signal observer if running (check both project-scoped and global observer)
for pid_file in "${PROJECT_DIR}/.observer.pid" "${CONFIG_DIR}/.observer.pid"; do

View File

@@ -64,6 +64,14 @@ _clv2_detect_project() {
fi
fi
# Compute hash from the original remote URL (legacy, for backward compatibility)
local legacy_hash_input="${remote_url:-$project_root}"
# Strip embedded credentials from remote URL (e.g., https://ghp_xxxx@github.com/...)
if [ -n "$remote_url" ]; then
remote_url=$(printf '%s' "$remote_url" | sed -E 's|://[^@]+@|://|')
fi
local hash_input="${remote_url:-$project_root}"
# Use SHA256 via python3 (portable across macOS/Linux, no shasum/sha256sum divergence)
project_id=$(printf '%s' "$hash_input" | python3 -c "import sys,hashlib; print(hashlib.sha256(sys.stdin.buffer.read()).hexdigest()[:12])" 2>/dev/null)
@@ -75,6 +83,17 @@ _clv2_detect_project() {
echo "fallback")
fi
# Backward compatibility: if credentials were stripped and the hash changed,
# check if a project dir exists under the legacy hash and reuse it
if [ "$legacy_hash_input" != "$hash_input" ]; then
local legacy_id
legacy_id=$(printf '%s' "$legacy_hash_input" | python3 -c "import sys,hashlib; print(hashlib.sha256(sys.stdin.buffer.read()).hexdigest()[:12])" 2>/dev/null)
if [ -n "$legacy_id" ] && [ -d "${_CLV2_PROJECTS_DIR}/${legacy_id}" ] && [ ! -d "${_CLV2_PROJECTS_DIR}/${project_id}" ]; then
# Migrate legacy directory to new hash
mv "${_CLV2_PROJECTS_DIR}/${legacy_id}" "${_CLV2_PROJECTS_DIR}/${project_id}" 2>/dev/null || project_id="$legacy_id"
fi
fi
# Export results
_CLV2_PROJECT_ID="$project_id"
_CLV2_PROJECT_NAME="$project_name"

View File

@@ -976,13 +976,120 @@ function runTests() {
assert.ok(result.output.includes('custom error'), 'Should include stderr output');
})) passed++; else failed++;
if (test('runCommand falls back to err.message when no stderr', () => {
// An invalid command that won't produce stderr through child process
const result = utils.runCommand('nonexistent_cmd_xyz_12345');
if (test('runCommand returns error output on failed command', () => {
// Use an allowed prefix with a nonexistent subcommand to reach execSync
const result = utils.runCommand('git nonexistent-subcmd-xyz-12345');
assert.strictEqual(result.success, false);
assert.ok(result.output.length > 0, 'Should have some error output');
})) passed++; else failed++;
// ── runCommand security: allowlist and metacharacter blocking ──
console.log('\nrunCommand Security (allowlist + metacharacters):');
if (test('runCommand blocks disallowed command prefix', () => {
const result = utils.runCommand('rm -rf /');
assert.strictEqual(result.success, false);
assert.ok(result.output.includes('unrecognized command prefix'), 'Should mention blocked prefix');
})) passed++; else failed++;
if (test('runCommand blocks curl command', () => {
const result = utils.runCommand('curl http://example.com');
assert.strictEqual(result.success, false);
assert.ok(result.output.includes('unrecognized command prefix'));
})) passed++; else failed++;
if (test('runCommand blocks bash command', () => {
const result = utils.runCommand('bash -c "echo hello"');
assert.strictEqual(result.success, false);
assert.ok(result.output.includes('unrecognized command prefix'));
})) passed++; else failed++;
if (test('runCommand blocks semicolon command chaining', () => {
const result = utils.runCommand('git status; echo pwned');
assert.strictEqual(result.success, false);
assert.ok(result.output.includes('metacharacters not allowed'), 'Should block semicolon chaining');
})) passed++; else failed++;
if (test('runCommand blocks pipe command chaining', () => {
const result = utils.runCommand('git log | cat');
assert.strictEqual(result.success, false);
assert.ok(result.output.includes('metacharacters not allowed'), 'Should block pipe chaining');
})) passed++; else failed++;
if (test('runCommand blocks ampersand command chaining', () => {
const result = utils.runCommand('git status && echo pwned');
assert.strictEqual(result.success, false);
assert.ok(result.output.includes('metacharacters not allowed'), 'Should block ampersand chaining');
})) passed++; else failed++;
if (test('runCommand blocks dollar sign command substitution', () => {
const result = utils.runCommand('git log $(whoami)');
assert.strictEqual(result.success, false);
assert.ok(result.output.includes('metacharacters not allowed'), 'Should block $ substitution');
})) passed++; else failed++;
if (test('runCommand blocks backtick command substitution', () => {
const result = utils.runCommand('git log `whoami`');
assert.strictEqual(result.success, false);
assert.ok(result.output.includes('metacharacters not allowed'), 'Should block backtick substitution');
})) passed++; else failed++;
if (test('runCommand allows metacharacters inside double quotes', () => {
// Semicolon inside quotes should not trigger metacharacter blocking
const result = utils.runCommand('node -e "console.log(1);process.exit(0)"');
assert.strictEqual(result.success, true);
})) passed++; else failed++;
if (test('runCommand allows metacharacters inside single quotes', () => {
const result = utils.runCommand("node -e 'process.exit(0);'");
assert.strictEqual(result.success, true);
})) passed++; else failed++;
if (test('runCommand blocks unquoted metacharacters alongside quoted ones', () => {
// Semicolon inside quotes is safe, but && outside is not
const result = utils.runCommand('git log "safe;part" && echo pwned');
assert.strictEqual(result.success, false);
assert.ok(result.output.includes('metacharacters not allowed'));
})) passed++; else failed++;
if (test('runCommand blocks prefix without trailing space', () => {
// "gitconfig" starts with "git" but not "git " — must be blocked
const result = utils.runCommand('gitconfig --list');
assert.strictEqual(result.success, false);
assert.ok(result.output.includes('unrecognized command prefix'));
})) passed++; else failed++;
if (test('runCommand allows npx prefix', () => {
const result = utils.runCommand('npx --version');
assert.strictEqual(result.success, true);
})) passed++; else failed++;
if (test('runCommand blocks newline command injection', () => {
const result = utils.runCommand('git status\necho pwned');
assert.strictEqual(result.success, false);
assert.ok(result.output.includes('metacharacters not allowed'), 'Should block newline injection');
})) passed++; else failed++;
if (test('runCommand blocks $() inside double quotes (shell still evaluates)', () => {
// $() inside double quotes is still evaluated by the shell, so block $ everywhere
const result = utils.runCommand('node -e "$(whoami)"');
assert.strictEqual(result.success, false);
assert.ok(result.output.includes('metacharacters not allowed'), 'Should block $ inside quotes');
})) passed++; else failed++;
if (test('runCommand blocks backtick inside double quotes (shell still evaluates)', () => {
const result = utils.runCommand('node -e "`whoami`"');
assert.strictEqual(result.success, false);
assert.ok(result.output.includes('metacharacters not allowed'), 'Should block backtick inside quotes');
})) passed++; else failed++;
if (test('runCommand error message does not leak command string', () => {
const secret = 'rm secret_password_123';
const result = utils.runCommand(secret);
assert.strictEqual(result.success, false);
assert.ok(!result.output.includes('secret_password_123'), 'Should not leak command contents');
})) passed++; else failed++;
// ── Round 31: getGitModifiedFiles with empty patterns ──
console.log('\ngetGitModifiedFiles empty patterns (Round 31):');