CVE-2021-39246
MEDIUMTorproject Tor Browser < 10.5.6 - Log Information Exposure
Title source: ruleDescription
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).
References (5)
Core 5
Core References
Exploit, Third Party Advisory x_refsource_misc
https://github.com/sickcodes/security/blob/master/advisories/SICK-2021-111.md
Exploit, Third Party Advisory x_refsource_misc
https://sick.codes/sick-2021-111
Third Party Advisory x_refsource_misc
https://www.privacyaffairs.com/cve-2021-39246-tor-vulnerability
Patch, Vendor Advisory x_refsource_misc
https://gitlab.torproject.org/tpo/core/tor/-/commit/80c404c4b79f3bcba3fc4585d4c62a62a04f3ed9
Vendor Advisory x_refsource_misc
https://gitlab.torproject.org/tpo/core/tor/-/merge_requests/434
Scores
CVSS v3
6.1
EPSS
0.0011
EPSS Percentile
28.7%
Attack Vector
PHYSICAL
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Details
CWE
CWE-532
Status
published
Products (2)
torproject/tor_browser
11.0 alpha2 (2 CPE variants)
torproject/tor_browser
< 10.5.6
Published
Sep 24, 2021
Tracked Since
Feb 18, 2026