CVE-2019-9749: High severity fluent bit by treasure data vulnerability
An issue was discovered in the MQTT input plugin in Fluent Bit through 1.0.4. When this plugin acts as an MQTT broker (server), it mishandles incoming network messages. After processing a crafted packet, the plugin's mqttpacketdrop function (in /plugins/inmqtt/mqttprot.c) executes the memmove() function with a negative size parameter. That leads to a crash of the whole Fluent Bit server via a SIGSEGV signal.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2019-9749?
CVE-2019-9749 is assigned a medium severity rating due to the potential for denial of service during message processing.
How do I fix CVE-2019-9749?
To fix CVE-2019-9749, upgrade Fluent Bit to version 1.0.5 or later.
What does CVE-2019-9749 affect?
CVE-2019-9749 affects the MQTT input plugin in Fluent Bit versions up to and including 1.0.4.
What type of vulnerability is CVE-2019-9749?
CVE-2019-9749 is a denial of service vulnerability due to improper handling of incoming network messages.
How can I determine if my system is vulnerable to CVE-2019-9749?
You can determine if your system is vulnerable to CVE-2019-9749 by checking if Fluent Bit is installed and if the version is 1.0.4 or earlier.