In Eclipse Mosquitto version 1.0 to 1.5.5 (inclusive) when a client publishes a retained message to a topic, then has its access to that topic revoked, the retained message will still be published to clients that subscribe to that topic in the future. In some applications this may result in clients being able cause effects that would otherwise not be allowed.

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

  - In Eclipse Mosquitto version 1.0 to 1.5.5 (inclusive) when a client publishes a retained message to a
    topic, then has its access to that topic revoked, the retained message will still be published to clients
    that subscribe to that topic in the future. In some applications this may result in clients being able
    cause effects that would otherwise not be allowed. (CVE-2018-12546)

  - When Eclipse Mosquitto version 1.0 to 1.5.5 (inclusive) is configured to use an ACL file, and that ACL
    file is empty, or contains only comments or blank lines, then Mosquitto will treat this as though no ACL
    file has been defined and use a default allow policy. The new behaviour is to have an empty ACL file mean
    that all access is denied, which is not a useful configuration but is not unexpected. (CVE-2018-12550)

  - When Eclipse Mosquitto version 1.0 to 1.5.5 (inclusive) is configured to use a password file for
    authentication, any malformed data in the password file will be treated as valid. This typically means
    that the malformed data becomes a username and no password. If this occurs, clients can circumvent
    authentication and get access to the broker by using the malformed username. In particular, a blank line
    will be treated as a valid empty username. Other security measures are unaffected. Users who have only
    used the mosquitto_passwd utility to create and modify their password files are unaffected by this
    vulnerability. (CVE-2018-12551)

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - In Eclipse Mosquitto version 1.0 to 1.5.5 (inclusive) when a client publishes a retained message to a
    topic, then has its access to that topic revoked, the retained message will still be published to clients
    that subscribe to that topic in the future. In some applications this may result in clients being able
    cause effects that would otherwise not be allowed. (CVE-2018-12546)

This update for mosquitto fixes the following issues :

Security issues fixed :

  - CVE-2018-12546: Fixed an issue with revoked access to     topics (bsc#1125019).

  - CVE-2018-12551: Fixed an issue which allowed malformed     data in the password file to be treated as valid     (bsc#1125020).

  - CVE-2018-12550: Fixed an an issue which treats an empty     ACL file wrongly (bsc#1125021).

Fixes for the following CVES :

  - CVE-2018-12546

  - CVE-2018-12550

  - CVE-2018-12551 

The list of other fixes addressed in version 1.5.6 is: Broker :

  - Fixed comment handling for config options that have     optional arguments.

  - Improved documentation around bridge topic remapping.

  - Handle mismatched handshakes (e.g. QoS1 PUBLISH with     QoS2 reply) properly.

  - Fix spaces not being allowed in the bridge     remote_username option. Closes #1131.

  - Allow broker to always restart on Windows when using     log_dest file. Closes #1080.

  - Fix Will not being sent for Websockets clients. Closes     #1143.

  - Windows: Fix possible crash when client disconnects.
    Closes #1137.

  - Fixed durable clients being unable to receive messages     when offline, when per_listener_settings was set to     true. Closes #1081.

  - Add log message for the case where a client is     disconnected for sending a topic with invalid UTF-8.
    Closes #1144.

Library :

  - Fix TLS connections not working over SOCKS.

  - Don't clear SSL context when TLS connection is closed,     meaning if a user provided an external SSL_CTX they have     less chance of leaking references.

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.

Three vulnerabilities were discovered in the Mosquitto MQTT broker, which could result in authentication bypass. Please refer to https://mosquitto.org/blog/2019/02/version-1-5-6-released/ for additional information.

ID	Name	Product	Family	Severity
424205	Alpine: multiple mosquitto packages: security update to 1.5.6-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	high
424205	Alpine: multiple mosquitto packages: security update to 1.5.6-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	high
405602	Alpine: mosquitto: security update to 1.4.15-r5	Tenable Cloud Security	Alpine Linux Local Security Checks	medium
405602	Alpine: mosquitto: security update to 1.4.15-r5	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	medium
405600	Alpine: mosquitto: security update to 1.4.15-r1	Tenable Cloud Security	Alpine Linux Local Security Checks	high
405600	Alpine: mosquitto: security update to 1.4.15-r1	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	high
400610	Alpine: multiple mosquitto packages: security update to 1.5.5-r1 (deprecated)	Tenable Cloud Security	Alpine Linux Local Security Checks	high
400610	Alpine: multiple mosquitto packages: security update to 1.5.5-r1 (deprecated)	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	high
122417	openSUSE Security Update : mosquitto (openSUSE-2019-233)	Nessus	SuSE Local Security Checks	high
122285	Fedora 28 : mosquitto (2019-8cbe2a05cd)	Nessus	Fedora Local Security Checks	high
122069	Debian DSA-4388-1 : mosquitto - security update	Nessus	Debian Local Security Checks	high

Detections

Analytics

CVE-2018-12546

medium

Tenable Plugins

high

high

medium

medium

high

high

high

high

high

high

high