7.5

CVE-2021-34548: torproject tor Authentication Bypass by Spoofing

CVSS: 7.5v3.1HighModified
AliasesUBUNTU-CVE-2021-34548DEBIAN-CVE-2021-34548
Published 29-06-2021Last modified 04-08-2024
Open JSON

Vulnerability summary

CVE-2021-34548 is a high (CVSS 7.5) Authentication Bypass by Spoofing vulnerability in torproject tor. EPSS estimates a 2.60% chance of exploitation in the next 30 days, higher than 85.1% of scored vulnerabilities.

Overall risk
31/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (NVD)
EPSS score
2.60%
0%100%
Low · -0.12 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-2021-003. An attacker can forge RELAY_END or RELAY_RESOLVED to bypass the intended access control for ending a stream.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

2.60%

Chance of exploitation in the next 30 days

Percentile

85%

Versus all other CVEs

30-day change

-0.12 pp

From 2.72% on 19-09-2026

19-09-202619-10-2026
EPSS score
2.60%

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< 0.4.2.7-1ubuntu0.1~esm1

3 vendors · 3 products

References

9 links