Resource exhaustion in Torproject Tor
CVE-2021-34549
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.
Vulnerability class: DoS (Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.016 (74.9th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 75th percentile — 74.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.016 · newest: 0.016 · change: 0.000
Affected products
Weakness classification (CWE)
References
- gitlab.torproject.org/tpo/core/tor/-/issues/40391 (Broken Link)
- blog.torproject.org/node/2041 (Release Notes, Vendor Advisory)
- security.gentoo.org/glsa/202107-25 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-34549?
- CVE-2021-34549 is a high-severity vulnerability in Torproject Tor, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2021-06-29.
- How severe is CVE-2021-34549?
- High severity. CVSS v3 base score is 7.5 out of 10.