Vulnerabilities > CVE-2021-39246 - Information Exposure Through Log Files vulnerability in Torproject TOR Browser

047910
CVSS 6.1 - MEDIUM
Attack vector
PHYSICAL
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
HIGH
Integrity impact
HIGH
Availability impact
NONE
low complexity
torproject
CWE-532
NVD
Published: 2021-09-24
Updated: 2024-11-21

Summary

Tor Browser through 10.5.6 and 11.x through 11.0a4 allows a correlation attack that can compromise the privacy of visits to v2 onion addresses. Exact timestamps of these onion-service visits are logged locally, and an attacker might be able to compare them to timestamp data collected by the destination server (or collected by a rogue site within the Tor network).

Vulnerable Configurations

Part Description Count
Application
Torproject
51
OS
Apple
1
OS
Linux
1
OS
Microsoft
1

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Fuzzing and observing application log data/errors for application mapping
    An attacker sends random, malformed, or otherwise unexpected messages to a target application and observes the application's log or error messages returned. Fuzzing techniques involve sending random or malformed messages to a target and monitoring the target's response. The attacker does not initially know how a target will respond to individual messages but by attempting a large number of message variants they may find a variant that trigger's desired behavior. In this attack, the purpose of the fuzzing is to observe the application's log and error messages, although fuzzing a target can also sometimes cause the target to enter an unstable state, causing a crash. By observing logs and error messages, the attacker can learn details about the configuration of the target application and might be able to cause the target to disclose sensitive information.

References