HOMEVULNERABILITIESCVE-2020-15166
HIGH

CVE-2020-15166

CWE-400Published: September 11, 2020· Updated: Jun 17, 2026

7.5
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2020-15166 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

Debian1 product(s)
debian linux
Fedora1 product(s)
fedora
zeromq1 product(s)
libzmq
Source: NVD CPE · 4 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/zeromq/libzmq/pull/3913
PATCHhttps://github.com/zeromq/libzmq/pull/3973
PATCHhttps://github.com/zeromq/libzmq/security/advisories/GHSA-25wp-cf8g-938m
PATCHhttps://github.com/zeromq/libzmq/pull/3913
PATCHhttps://github.com/zeromq/libzmq/pull/3973
PATCHhttps://github.com/zeromq/libzmq/security/advisories/GHSA-25wp-cf8g-938m
ADVISORYhttps://lists.debian.org/debian-lts-announce/2020/11/msg00017.html
ADVISORYhttps://security.gentoo.org/glsa/202009-12
ADVISORYhttps://lists.debian.org/debian-lts-announce/2020/11/msg00017.html
ADVISORYhttps://security.gentoo.org/glsa/202009-12

All References (14)

→
https://github.com/zeromq/libzmq/pull/3913Patch · Third Party Advisory
→
https://github.com/zeromq/libzmq/pull/3973Patch · Third Party Advisory
→
https://github.com/zeromq/libzmq/security/advisories/GHSA-25wp-cf8g-938mPatch · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2020/11/msg00017.htmlMailing List · Third Party Advisory
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BZ5IMNQXDB52JFBXHFLK4AHVORFELNNG/
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YFW2ZELCCPS4VLU4OSJOH5YL6KFKTFYW/
→
https://security.gentoo.org/glsa/202009-12Third Party Advisory
→
https://github.com/zeromq/libzmq/pull/3913Patch · Third Party Advisory
→
https://github.com/zeromq/libzmq/pull/3973Patch · Third Party Advisory
→
https://github.com/zeromq/libzmq/security/advisories/GHSA-25wp-cf8g-938mPatch · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2020/11/msg00017.htmlMailing List · Third Party Advisory
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BZ5IMNQXDB52JFBXHFLK4AHVORFELNNG/
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YFW2ZELCCPS4VLU4OSJOH5YL6KFKTFYW/
→
https://security.gentoo.org/glsa/202009-12Third Party Advisory

Quick Facts

CVE IDCVE-2020-15166
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-400
CISA KEVNo
Affected3 vendor(s)
PublishedSep 11, 2020

Related CVEs (CWE-400)

CVE-2013-20004
9.8
CVE-2019-10750
9.8
CVE-2019-10747
9.8
CVE-2019-2259
9.8
CVE-2015-4412
9.8
CVE-2023-30769
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2020-15166 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
← All Vulnerabilities·Search for CVE-2020-15166·NVD