What is CVE-2021-32567?

CVE-2021-32567 is a high-severity vulnerability in Apache Traffic Server, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2021-06-30.

How severe is CVE-2021-32567?

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

Improper input validation in Apache Traffic Server

CVE-2021-32567

Improper Input Validation vulnerability in HTTP/2 of Apache Traffic Server allows an attacker to DOS the server. This issue affects Apache Traffic Server 7.0.0 to 7.1.12, 8.0.0 to 8.1.1, 9.0.0 to 9.0.1.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2021-06-30 · 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: 0.024 (83.8th percentile), scored 2026-10-07.

Low probability of exploitation in the next 30 days, but still tracked. 84th percentile — 83.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.024 · newest: 0.024 · change: 0.000

Affected products

Apache Traffic Server
Apache Software Foundation Traffic Server — versions Apache Traffic Server 7.0.0 to 7.1.12, 8.0.0 to 8.1.1, 9.0.0 to 9.0.1
Debian Linux — versions 10.0

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

lists.apache.org/thread.html/ra1a41ff92a70d25bf576d7da2590575e8ff430393a3f4a0c3… (Mailing List, Vendor Advisory)
www.debian.org/security/2021/dsa-4957 (vendor-advisory, Third Party Advisory)

Frequently asked questions

What is CVE-2021-32567?: CVE-2021-32567 is a high-severity vulnerability in Apache Traffic Server, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2021-06-30.
How severe is CVE-2021-32567?: High severity. CVSS v3 base score is 7.5 out of 10.