7.5

CVE-2021-34549: torproject tor Uncontrolled Resource Consumption

CVSS: 7.5v3.1HighModified
AliasesUBUNTU-CVE-2021-34549DEBIAN-CVE-2021-34549
Published 29-06-2021Last modified 04-08-2024
Open JSON

Vulnerability summary

CVE-2021-34549 is a high (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in torproject tor. EPSS estimates a 1.61% chance of exploitation in the next 30 days, higher than 75.5% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (NVD)
EPSS score
1.61%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 6 · Related 4
DSA-4932-1MGASA-2021-0293OPENSUSE-SU-2021:0926-1OPENSUSE-SU-2021:0941-1OPENSUSE-SU-2024:11469-1USN-5036-1

Timeline

  1. 29-06-2021
    PublishedVulnerability first disclosed.
  2. 04-08-2024
    Last modifiedVulnerability information updated.

Description

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 metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

1.61%

Chance of exploitation in the next 30 days

Percentile

76%

Versus all other CVEs

30-day change

0.00 pp

From 1.61% on 19-09-2026

19-09-202619-10-2026
EPSS score
1.61%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • tor< 0.4.5.9-1
Torproject1 product
  • tor< 0.3.5.15 | ≥ 0.4.0.0, < 0.4.4.9 | ≥ 0.4.5.0, < 0.4.5.9 | ≥ 0.4.6.0, < 0.4.6.5
Ubuntu1 product
  • tor< 0.2.9.14-1ubuntu1~16.04.3+esm1 | < 0.3.2.10-1ubuntu0.2~esm2 | < 0.4.2.7-1ubuntu0.1~esm1

3 vendors · 3 products

References

8 links