CVE-2020-8516

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.5% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2020-02-02 · updated 2026-06-17

Description

The daemon in Tor through 0.4.1.8 and 0.4.2.x through 0.4.2.6 does not verify that a rendezvous node is known before attempting to connect to it, which might make it easier for remote attackers to discover circuit information. NOTE: The network team of Tor claims this is an intended behavior and not a vulnerability

Affected products

torproject Tor: through 0.4.1.8; from 0.4.2.0 through 0.4.2.6

References

https://lists.torproject.org/pipermail/tor-dev/2020-February/014146.html
https://lists.torproject.org/pipermail/tor-dev/2020-February/014147.html
https://security-tracker.debian.org/tracker/CVE-2020-8516
https://trac.torproject.org/projects/tor/ticket/33129
https://www.hackerfactor.com/blog/index.php?/archives/868-Deanonymizing-Tor-Circuits.html
https://lists.torproject.org/pipermail/tor-dev/2020-February/014146.html
https://lists.torproject.org/pipermail/tor-dev/2020-February/014147.html
https://security-tracker.debian.org/tracker/CVE-2020-8516
https://trac.torproject.org/projects/tor/ticket/33129
https://www.hackerfactor.com/blog/index.php?/archives/868-Deanonymizing-Tor-Circuits.html

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