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.

The remote Ubuntu 16.04 ESM / 18.04 ESM / 20.04 ESM host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-4920-1 advisory.

  - In ZeroMQ libzmq before 4.0.9, 4.1.x before 4.1.7, and 4.2.x before 4.3.2, a remote, unauthenticated     client connecting to a libzmq application, running with a socket listening with CURVE     encryption/authentication enabled, may cause a stack overflow and overwrite the stack with arbitrary data,     due to a buffer overflow in the library. Users running public servers with the above configuration are     highly encouraged to upgrade as soon as possible, as there are no known mitigations. (CVE-2019-13132)

  - 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. (CVE-2020-15166)

  - An uncontrolled resource consumption (memory leak) flaw was found in the ZeroMQ client in versions before     4.3.3 in src/pipe.cpp. This issue causes a client that connects to multiple malicious or compromised     servers to crash. The highest threat from this vulnerability is to system availability. (CVE-2021-20234)

  - There's a flaw in the zeromq server in versions before 4.3.3 in src/decoder_allocators.hpp. The decoder     static allocator could have its sized changed, but the buffer would remain the same as it is a static     buffer. A remote, unauthenticated attacker who sends a crafted request to the zeromq server could trigger     a buffer overflow WRITE of arbitrary data if CURVE/ZAP authentication is not enabled. The greatest impact     of this flaw is to application availability, data integrity, and confidentiality. (CVE-2021-20235)

  - An uncontrolled resource consumption (memory leak) flaw was found in ZeroMQ's src/xpub.cpp in versions     before 4.3.3. This flaw allows a remote unauthenticated attacker to send crafted PUB messages that consume     excessive memory if the CURVE/ZAP authentication is disabled on the server, causing a denial of service.
    The highest threat from this vulnerability is to system availability. (CVE-2021-20237)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Google's oss-fuzz project reports :

Denial-of-Service on CURVE/ZAP-protected servers by unauthenticated clients. 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 update for zeromq fixes the following issues :

CVE-2020-15166: Fixed the possibility of unauthenticated clients causing a denial-of-service (bsc#1176116).

Fixed a heap overflow when receiving malformed ZMTP v1 packets (bsc#1176256)

Fixed a memory leak in client induced by malicious server(s) without CURVE/ZAP (bsc#1176257)

Fixed memory leak when processing PUB messages with metadata (bsc#1176259)

Fixed a stack overflow in PUB/XPUB subscription store (bsc#1176258)

Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

This update for zeromq fixes the following issues :

  - CVE-2020-15166: Fixed the possibility of unauthenticated     clients causing a denial-of-service (bsc#1176116).

  - Fixed a heap overflow when receiving malformed ZMTP v1     packets (bsc#1176256)

  - Fixed a memory leak in client induced by malicious     server(s) without CURVE/ZAP (bsc#1176257)

  - Fixed memory leak when processing PUB messages with     metadata (bsc#1176259)

  - Fixed a stack overflow in PUB/XPUB subscription store     (bsc#1176258)

This update was imported from the SUSE:SLE-15:Update update project.

It was discovered that ZeroMQ, a lightweight messaging kernel library does not properly handle connecting peers before a handshake is completed. A remote, unauthenticated client connecting to an application using the libzmq library, running with a socket listening with CURVE encryption/authentication enabled can take advantage of this flaw to cause a denial of service affecting authenticated and encrypted clients.

For Debian 9 stretch, this problem has been fixed in version 4.2.1-4+deb9u3.

We recommend that you upgrade your zeromq3 packages.

For the detailed security status of zeromq3 please refer to its security tracker page at:
https://security-tracker.debian.org/tracker/zeromq3

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Fix for #1876738 and #1876689

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

An update of the zeromq package has been released.

The remote host is affected by the vulnerability described in GLSA-202009-12 (ZeroMQ: Denial of service)

    It was discovered that ZeroMQ does not properly handle connecting peers       before a handshake is completed.
  Impact :

    An unauthenticated remote attacker able to connect to a ZeroMQ endpoint,       even with CURVE encryption/authentication enabled, can cause a Denial of       Service condition.
  Workaround :

    There is no known workaround at this time.

It was discovered that ZeroMQ, a lightweight messaging kernel library does not properly handle connecting peers before a handshake is completed. A remote, unauthenticated client connecting to an application using the libzmq library, running with a socket listening with CURVE encryption/authentication enabled can take advantage of this flaw to cause a denial of service affecting authenticated and encrypted clients.

ID	Name	Product	Family	Severity
183116	Ubuntu 16.04 ESM / 18.04 ESM / 20.04 ESM : ZeroMQ vulnerabilities (USN-4920-1)	Nessus	Ubuntu Local Security Checks	critical
149973	FreeBSD : libzmq4 -- Denial of Service (21ec4428-bdaa-11eb-a04e-641c67a117d8)	Nessus	FreeBSD Local Security Checks	high
143658	SUSE SLED15 / SLES15 Security Update : zeromq (SUSE-SU-2020:3264-1)	Nessus	SuSE Local Security Checks	high
142950	openSUSE Security Update : zeromq (openSUSE-2020-1910)	Nessus	SuSE Local Security Checks	high
142925	openSUSE Security Update : zeromq (openSUSE-2020-1907)	Nessus	SuSE Local Security Checks	high
142861	Debian DLA-2443-1 : zeromq3 security update	Nessus	Debian Local Security Checks	high
140759	Fedora 32 : zeromq (2020-08402f4071)	Nessus	Fedora Local Security Checks	high
140664	Photon OS 2.0: Zeromq PHSA-2020-2.0-0281	Nessus	PhotonOS Local Security Checks	high
140567	GLSA-202009-12 : ZeroMQ: Denial of service	Nessus	Gentoo Local Security Checks	high
140537	Photon OS 3.0: Zeromq PHSA-2020-3.0-0139	Nessus	PhotonOS Local Security Checks	high
140459	Photon OS 1.0: Zeromq PHSA-2020-1.0-0322	Nessus	PhotonOS Local Security Checks	high
140302	Debian DSA-4761-1 : zeromq3 - security update	Nessus	Debian Local Security Checks	high

Detections

Analytics

CVE-2020-15166

high

Tenable Plugins

critical

high

high

high

high

high

high

high

high

high

high

high