Description
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 mqtt_packet_drop function (in /plugins/in_mqtt/mqtt_prot.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.
Scores
CVSS v3
7.5
EPSS
0.0101
EPSS Percentile
77.2%
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-681
Status
published
Products (1)
treasuredata/fluent_bit
< 1.0.4
Published
Mar 13, 2019
Tracked Since
Feb 18, 2026