CVE-2020-15166

HIGH

libzmq < 4.3.3 - Denial of Service via TCP Transport Endpoint

Title source: llm
STIX 2.1

Description

In ZeroMQ before version 4.3.3, there is a denial-of-service vulnerability. Users with TCP transport public endpoints, even with CURVE/ZAP enabled, are impacted. If a raw TCP socket is opened and connected to an endpoint that is fully configured with CURVE/ZAP, legitimate clients will not be able to exchange any message. Handshakes complete successfully, and messages are delivered to the library, but the server application never receives them. This is patched in version 4.3.3.

References (7)

Core 7
Core References
Patch, Third Party Advisory x_refsource_confirm
https://github.com/zeromq/libzmq/security/advisories/GHSA-25wp-cf8g-938m
Patch, Third Party Advisory x_refsource_misc
https://github.com/zeromq/libzmq/pull/3913
Patch, Third Party Advisory x_refsource_misc
https://github.com/zeromq/libzmq/pull/3973
Third Party Advisory vendor-advisory x_refsource_gentoo
https://security.gentoo.org/glsa/202009-12
Mailing List, Third Party Advisory mailing-list x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2020/11/msg00017.html

Scores

CVSS v3 7.5
EPSS 0.0341
EPSS Percentile 87.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Details

CWE
CWE-400
Status published
Products (4)
debian/debian_linux 9.0
fedoraproject/fedora 32
fedoraproject/fedora 33
zeromq/libzmq < 4.3.3
Published Sep 11, 2020
Tracked Since Feb 18, 2026