CVE-2021-34549: High severity tor project tor vulnerability

Published Jun 29, 2021
·
Updated

An issue was discovered in Tor before 0.4.6.5, aka TROVE-2021-005. Hashing is mishandled for certain retrieval of circuit data. Consequently. an attacker can trigger the use of an attacker-chosen circuit ID to cause algorithm inefficiency.

Affected Software

4 affected components
torproject Tor<0.3.5.15
torproject Tor>=0.4.0.0<0.4.4.9
torproject Tor>=0.4.5.0<0.4.5.9
torproject Tor>=0.4.6.0<0.4.6.5

Event History

Jun 29, 2021
CVE Published
via MITRE·11:08 AM
Data Sourced
via MITRE·11:08 AM
Description
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Frequently Asked Questions

1

What is CVE-2021-34549?

CVE-2021-34549 is a vulnerability discovered in Tor before 0.4.6.5, which mishandles hashing for certain retrieval of circuit data, allowing an attacker to cause algorithm inefficiency.

2

What is the severity of CVE-2021-34549?

CVE-2021-34549 has a severity rating of 7.5 (High).

3

How does CVE-2021-34549 affect Torproject Tor?

CVE-2021-34549 affects Torproject Tor versions up to and including 0.4.6.5.

4

How can an attacker exploit CVE-2021-34549?

An attacker can exploit CVE-2021-34549 by triggering the use of an attacker-chosen circuit ID, leading to algorithm inefficiency.

5

How can I fix CVE-2021-34549?

To fix CVE-2021-34549, update Torproject Tor to version 0.4.6.6 or later.

Contact

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