fix(g2): Session-Revocation bei Passwortaenderung auf beiden Pfaden

Befund differenzierter als Plan annahm: Reset-via-Token revocierte Sessions bereits korrekt, aber Profil-/Admin-Pfad (users.py PATCH -> update_user mit new_password) liess alle anderen Sessions aktiv — ein Angreifer mit gestohlener Session blieb aktiv.

Fix nach DRY: revoke_user_redis_sessions(user_id)-Helper in app/core/auth.py extrahiert (scan_iter session:* + user_id-Match + delete, never-raises), von beiden Pfaden genutzt: confirm_password_reset ersetzt den Inline-Duplikat-Block, update_user ruft den Helper wenn new_password gesetzt wurde. Postgres sessions-Tabelle bleibt unberuehrt (Audit-Trail by Design, Redis ist Runtime-Store).

Beweis: auth+user_service+rbac_comprehensive 120/120 gruen in 144s; ruff clean.

app/core/auth.py

@@ -85,6 +85,38 @@ def generate_csrf_token() -> str:
     return secrets.token_urlsafe(32)
 
 
+async def revoke_user_redis_sessions(user_id: str | uuid.UUID) -> int:
+    """Delete every active Redis session belonging to the user (G2).
+
+    Shared by both password-change paths (token reset + profile/admin change):
+    after a password change, stolen or lingering sessions must die.
+
+    Returns the number of deleted session keys. Never raises — a Redis outage
+    must not break the password change itself.
+    """
+    try:
+        redis = get_redis()
+        deleted = 0
+        async for key in redis.scan_iter(match="session:*", count=100):
+            raw = await redis.get(key)
+            if raw is None:
+                continue
+            try:
+                import json
+
+                session_data = json.loads(raw)
+            except (json.JSONDecodeError, TypeError):
+                continue
+            if session_data.get("user_id") == str(user_id):
+                await redis.delete(key)
+                deleted += 1
+                logger.info("Deleted session %s for user %s", key, user_id)
+        return deleted
+    except Exception:
+        logger.warning("Failed to invalidate Redis sessions for user %s", user_id, exc_info=True)
+        return 0
+
+
 def hash_token(token: str) -> str:
     """SHA-256 hash a token for storage."""
     return hashlib.sha256(token.encode()).hexdigest()

app/services/auth_service.py

@@ -15,7 +15,6 @@ from app.config import get_settings
 from app.core.audit import log_audit
 from app.core.auth import (
     create_session,
-    get_redis,
     get_session_data,
     hash_password,
     hash_token,
@@ -328,24 +327,10 @@ class AuthService:
         await db.flush()
 
         # Invalidate all active Redis sessions for this user
-        try:
+        # (shared helper — same mechanism as the profile/admin change path)
-            redis = get_redis()
+        from app.core.auth import revoke_user_redis_sessions
-            # Scan for session keys and check which belong to this user
-            import json
 
-            async for key in redis.scan_iter(match="session:*", count=100):
+        await revoke_user_redis_sessions(user.id)
-                raw = await redis.get(key)
-                if raw is None:
-                    continue
-                try:
-                    session_data = json.loads(raw)
-                except (json.JSONDecodeError, TypeError):
-                    continue
-                if session_data.get("user_id") == str(user.id):
-                    await redis.delete(key)
-                    logger.info("Deleted session %s for user %s after password reset", key, user.id)
-        except Exception:
-            logger.warning("Failed to invalidate Redis sessions for user %s", user.id, exc_info=True)
 
         # Audit log entry for password reset — use separate API session (crm_api)
         # to avoid requiring audit_log INSERT grants on crm_auth

app/services/user_service.py

@@ -201,6 +201,14 @@ class UserService:
             user.password_hash = hash_password(new_password)
 
         await db.flush()
+
+        # G2: after a profile/admin password change, kill all other sessions —
+        # a stolen or lingering session must not survive the change.
+        if new_password is not None:
+            from app.core.auth import revoke_user_redis_sessions
+
+            await revoke_user_redis_sessions(user.id)
+
         return user, user_tenant
 
     async def delete_user(