CVE-2022-33903: High severity torproject Tor vulnerability

Published Jun 20, 2022
·
Updated

A Denial of Service issue was fixed in tor 0.4.7.8 related to congestion control. RTT estimation can become wedged, seriously degrading congestion control performance on all circuits. This impacts clients, onion services, and relays, and can be triggered remotely by a malicious endpoint.

References: https://gitlab.torproject.org/tpo/core/tor/-/issues/40626 https://lists.torproject.org/pipermail/tor-announce/2022-June/000242.html https://github.com/torproject/tor/commit/5a25374209689466e10906a77e66ad717a615a02 https://github.com/torproject/tor/commit/b0496d40197dd5b4fb7b694c1410082d4e34dda6

Other sources

Tor 0.4.7.x before 0.4.7.8 allows a denial of service via the wedging of RTT estimation.

MITRE

Affected Software

2 affected componentsFixes available
torproject Tor>=0.4.7.1<0.4.7.8
debian/tor
0.4.5.16-10.4.7.16-10.4.8.16-10.4.8.22-10.4.9.5-1

Event History

Jun 20, 2022
Data Sourced
via Red Hat·11:11 AM
DescriptionSeverityAffected Software
Jul 17, 2022
CVE Published
via MITRE·12:00 AM
Data Sourced
via MITRE·12:00 AM
Description
Feb 25, 2026
Data Sourced
via Debian·04:33 PM
DescriptionAffected Software
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Frequently Asked Questions

1

What is the vulnerability ID for this issue?

The vulnerability ID for this issue is CVE-2022-33903.

2

What is the severity of CVE-2022-33903?

The severity of CVE-2022-33903 is high with a severity value of 7.5.

3

How does CVE-2022-33903 impact Tor 0.4.7.x before 0.4.7.8?

CVE-2022-33903 allows a denial of service via the wedging of RTT estimation in Tor 0.4.7.x before 0.4.7.8.

4

What is the affected software?

The affected software is Tor 0.4.7.x before 0.4.7.8 and Torproject Tor.

5

How can I fix CVE-2022-33903?

To fix CVE-2022-33903, you should upgrade to Tor version 0.4.7.8 or higher.

Contact

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