Resource exhaustion in Torproject Tor

CVE-2019-8955

In Tor before 0.3.3.12, 0.3.4.x before 0.3.4.11, 0.3.5.x before 0.3.5.8, and 0.4.x before 0.4.0.2-alpha, remote denial of service against Tor clients and relays can occur via memory exhaustion in the KIST cell scheduler.

EPSS: 0.046 (90.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

  • Torproject Tor — versions 0.3.4.0, 0.3.4.1, 0.3.4.2
  • N/a — versions n/a

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2019-8955?
CVE-2019-8955 is a high-severity vulnerability in Torproject Tor, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2019-02-21.
How severe is CVE-2019-8955?
High severity. CVSS v3 base score is 7.5 out of 10.