What is CVE-2018-25021?

CVE-2018-25021 is a high-severity vulnerability in Toktok Toxcore, classified under Improper Resource Shutdown or Release. CVSS score: 7.5/10. Published 2021-12-13.

How severe is CVE-2018-25021?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Toktok Toxcore

CVE-2018-25021

The TCP Server module in toxcore before 0.2.8 doesn't free the TCP priority queue under certain conditions, which allows a remote attacker to exhaust the system's memory, causing a denial of service (DoS).

Published 2021-12-13 · last modified 2026-06-17.

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: 0.023 (82.4th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 82nd percentile — 82.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.023 · newest: 0.023 · change: 0.000

Affected products

Toktok Toxcore

Weakness classification (CWE)

CWE-404 — Improper Resource Shutdown or Release

References

github.com/TokTok/c-toxcore/issues/1214 (Exploit, Third Party Advisory)
github.com/TokTok/c-toxcore/pull/1216 (Third Party Advisory)
blog.tox.chat/2018/10/memory-leak-bug-and-new-toxcore-release-fixing-it/ (Third Party Advisory)

Frequently asked questions

What is CVE-2018-25021?: CVE-2018-25021 is a high-severity vulnerability in Toktok Toxcore, classified under Improper Resource Shutdown or Release. CVSS score: 7.5/10. Published 2021-12-13.
How severe is CVE-2018-25021?: High severity. CVSS v3 base score is 7.5 out of 10.