release: v0.39.0 — security hardening, 12 fixes (#171)

* Security: harden auth, CSRF, SSRF, XSS, and env race conditions

Twelve fixes from a full security audit:

CRITICAL
- Add CSRF Origin/Referer validation on all POST endpoints
  (prevents cross-origin abuse of self-update, settings, file ops)

HIGH
- Unify password hashing: config.py now uses PBKDF2 (600k iters)
  instead of single-iteration SHA-256
- Add per-IP rate limiting on login (5 attempts/60s, 429 on excess)

MEDIUM
- Validate session IDs as hex-only before filesystem operations
  (prevents path traversal via crafted session ID)
- SSRF: resolve DNS before private-IP check in model fetching
  (prevents DNS rebinding to internal services)
- Warn loudly when binding non-loopback without password set
- SSE env var mutations: wrap sync chat + streaming restore in _ENV_LOCK
- Force Content-Disposition:attachment for HTML/XHTML/SVG uploads
  (prevents stored XSS via uploaded files)

LOW
- Extend HMAC session signature from 64 to 128 bits
- Add resolve()+relative_to() check on skills path construction
- Set Secure flag on session cookie when connection is HTTPS
- Sanitize exception messages to strip filesystem paths

No breaking changes. All fixes are backward-compatible.

* fix: use getattr for Secure cookie SSL detection

handler.request.getpeercert raises AttributeError on plain sockets
(non-SSL). Use getattr(..., None) to safely check for SSL.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* tests: add sprint 29 security hardening coverage (PR #171)

33 tests covering all 12 security fixes:
- CSRF origin/referer validation
- Login rate limiting (5 attempts/60s)
- Session ID hex validation (path traversal prevention)
- Error path sanitization (_sanitize_error)
- Secure cookie getattr safety
- HMAC signature length (64->128 bit)
- Skills path traversal prevention
- Content-Disposition for HTML/SVG/XHTML
- PBKDF2 password hashing verification
- Non-loopback startup warning
- SSRF DNS guard code presence
- _ENV_LOCK export from streaming module

* release: v0.39.0 — security hardening, 12 fixes (#171)

---------

Co-authored-by: betamod <matthew.sloly@gmail.com>
Co-authored-by: Nathan Esquenazi <nesquena@gmail.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

api/streaming.py

@@ -379,14 +379,15 @@ def _run_agent_streaming(session_id, msg_text, model, workspace, stream_id, atta
                 usage['last_prompt_tokens'] = getattr(_cc, 'last_prompt_tokens', 0) or 0
             put('done', {'session': s.compact() | {'messages': s.messages, 'tool_calls': tool_calls}, 'usage': usage})
           finally:
-            if old_cwd is None: os.environ.pop('TERMINAL_CWD', None)
-            else: os.environ['TERMINAL_CWD'] = old_cwd
-            if old_exec_ask is None: os.environ.pop('HERMES_EXEC_ASK', None)
-            else: os.environ['HERMES_EXEC_ASK'] = old_exec_ask
-            if old_session_key is None: os.environ.pop('HERMES_SESSION_KEY', None)
-            else: os.environ['HERMES_SESSION_KEY'] = old_session_key
-            if old_hermes_home is None: os.environ.pop('HERMES_HOME', None)
-            else: os.environ['HERMES_HOME'] = old_hermes_home
+            with _ENV_LOCK:
+              if old_cwd is None: os.environ.pop('TERMINAL_CWD', None)
+              else: os.environ['TERMINAL_CWD'] = old_cwd
+              if old_exec_ask is None: os.environ.pop('HERMES_EXEC_ASK', None)
+              else: os.environ['HERMES_EXEC_ASK'] = old_exec_ask
+              if old_session_key is None: os.environ.pop('HERMES_SESSION_KEY', None)
+              else: os.environ['HERMES_SESSION_KEY'] = old_session_key
+              if old_hermes_home is None: os.environ.pop('HERMES_HOME', None)
+              else: os.environ['HERMES_HOME'] = old_hermes_home
 
     except Exception as e:
         print('[webui] stream error:\n' + traceback.format_exc(), flush=True)