Medium severity · published Sep 24, 2021
CVE-2021-39246
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
6.1
CVSS
0.5%
EPSS
No
On KEV
Description
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).
CVSS vector
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Attack vector
Physical
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 41% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
TB
Tor Browser · Torproject
through 10.5.6; 11.0; 11.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-39246
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-39246
Exploit
https://github.com/sickcodes/security/blob/master/advisories/SICK-2021-111.md
Patch
https://gitlab.torproject.org/tpo/core/tor/-/commit/80c404c4b79f3bcba3fc4585d4c62a62a04f3ed9
Vendor Advisory
https://gitlab.torproject.org/tpo/core/tor/-/merge_requests/434
Exploit
https://sick.codes/sick-2021-111
Third Party Advisory
https://www.privacyaffairs.com/cve-2021-39246-tor-vulnerability
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