CVE-2021-34549

mediumpriority · track · 31EPSS 0.016 · 76 %ileEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

1.61% (76th) EPSS

CVSS 5 · medium

Is it mine?

12 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · nvd

EPSS · scored 2026-10-27

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.

cvss

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5–7.5

v2.05mediumAV:N/AC:L/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 10 · impact 2.9

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.17.5highAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-400USprimaryCWE-755US

affected products (12)

Products and version ranges known to be affected.

n/a n/a≤ n/aenisa_euvdEU
The Tor Project, Inc. Tor≤ 0.3.5.15fstec_bduRU
The Tor Project, Inc. Tor0.4.0.0 → 0.4.4.9fstec_bduRU
The Tor Project, Inc. Tor0.4.5.0 → 0.4.5.9fstec_bduRU
The Tor Project, Inc. Tor0.4.6.0 → 0.4.6.5fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 10fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 9fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 8fstec_bduRU
torproject tor< 0.3.5.15nvdUScpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:*
torproject tor0.4.0.0 → 0.4.4.9nvdUScpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:*
torproject tor0.4.5.0 → 0.4.5.9nvdUScpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:*
torproject tor0.4.6.0 → 0.4.6.5nvdUScpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:*

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu nvd NVD CVE.org MITRE

published 2021-06-29modified 2026-06-17

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references (15)

External citations — patches, advisories, analysis.

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