The rend_service_intro_established function in or/rendservice.c in Tor before 0.2.8.15, 0.2.9.x before 0.2.9.12, 0.3.0.x before 0.3.0.11, 0.3.1.x before 0.3.1.7, and 0.3.2.x before 0.3.2.1-alpha, when SafeLogging is disabled, allows attackers to obtain sensitive information by leveraging access to the log files of a hidden service, because uninitialized stack data is included in an error message about construction of an introduction point circuit.
Information written to log files can be of a sensitive nature and give valuable guidance to an attacker or expose sensitive user information.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Tor | Torproject | * | 0.2.8.14 (including) |
| Tor | Torproject | 0.2.9.0 (including) | 0.2.9.0 (including) |
| Tor | Torproject | 0.2.9.0-alpha (including) | 0.2.9.0-alpha (including) |
| Tor | Torproject | 0.2.9.1-alpha (including) | 0.2.9.1-alpha (including) |
| Tor | Torproject | 0.2.9.2-alpha (including) | 0.2.9.2-alpha (including) |
| Tor | Torproject | 0.2.9.3-alpha (including) | 0.2.9.3-alpha (including) |
| Tor | Torproject | 0.2.9.4-alpha (including) | 0.2.9.4-alpha (including) |
| Tor | Torproject | 0.2.9.5-alpha (including) | 0.2.9.5-alpha (including) |
| Tor | Torproject | 0.2.9.6 (including) | 0.2.9.6 (including) |
| Tor | Torproject | 0.2.9.8 (including) | 0.2.9.8 (including) |
| Tor | Torproject | 0.2.9.9 (including) | 0.2.9.9 (including) |
| Tor | Torproject | 0.2.9.10 (including) | 0.2.9.10 (including) |
| Tor | Torproject | 0.2.9.11 (including) | 0.2.9.11 (including) |
| Tor | Torproject | 0.3.0.0 (including) | 0.3.0.0 (including) |
| Tor | Torproject | 0.3.0.1-alpha (including) | 0.3.0.1-alpha (including) |
| Tor | Torproject | 0.3.0.2-alpha (including) | 0.3.0.2-alpha (including) |
| Tor | Torproject | 0.3.0.3-alpha (including) | 0.3.0.3-alpha (including) |
| Tor | Torproject | 0.3.0.4-rc (including) | 0.3.0.4-rc (including) |
| Tor | Torproject | 0.3.0.5-rc (including) | 0.3.0.5-rc (including) |
| Tor | Torproject | 0.3.0.6 (including) | 0.3.0.6 (including) |
| Tor | Torproject | 0.3.0.7 (including) | 0.3.0.7 (including) |
| Tor | Torproject | 0.3.0.8 (including) | 0.3.0.8 (including) |
| Tor | Torproject | 0.3.0.9 (including) | 0.3.0.9 (including) |
| Tor | Torproject | 0.3.0.10 (including) | 0.3.0.10 (including) |
| Tor | Torproject | 0.3.1.1-alpha (including) | 0.3.1.1-alpha (including) |
| Tor | Torproject | 0.3.1.2-alpha (including) | 0.3.1.2-alpha (including) |
| Tor | Torproject | 0.3.1.3-alpha (including) | 0.3.1.3-alpha (including) |
| Tor | Torproject | 0.3.1.4-alpha (including) | 0.3.1.4-alpha (including) |
| Tor | Torproject | 0.3.1.5-alpha (including) | 0.3.1.5-alpha (including) |
| Tor | Torproject | 0.3.1.6-alpha (including) | 0.3.1.6-alpha (including) |
| Tor | Torproject | 0.3.2 (including) | 0.3.2 (including) |
| Tor | Ubuntu | artful | * |
| Tor | Ubuntu | upstream | * |
| Tor | Ubuntu | xenial | * |
| Tor | Ubuntu | zesty | * |
While logging all information may be helpful during development stages, it is important that logging levels be set appropriately before a product ships so that sensitive user data and system information are not accidentally exposed to potential attackers. Different log files may be produced and stored for: