Buffer overflow in Zeromq

CVE-2021-20236

A flaw was found in the ZeroMQ server in versions before 4.3.3. This flaw allows a malicious client to cause a stack buffer overflow on the server by sending crafted topic subscription requests and then unsubscribing. The highest threat fr…

Vulnerability class: Buffer Overflow

EPSS: 0.016 (72.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-20236?
CVE-2021-20236 is a critical-severity vulnerability in Zeromq, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2021-05-28.
How severe is CVE-2021-20236?
Critical severity. CVSS v3 base score is 9.8 out of 10.