CVE-2018-19417

Severity: critical (CVSS 10.0 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 5.7% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2018-11-21 · updated 2026-06-17
Weakness: CWE-119

Description

An issue was discovered in the MQTT server in Contiki-NG before 4.2. The function parse_publish_vhdr() that parses MQTT PUBLISH messages with a variable length header uses memcpy to input data into a fixed size buffer. The allocated buffer can fit only MQTT_MAX_TOPIC_LENGTH (default 64) bytes, and a length check is missing. This could lead to Remote Code Execution via a stack-smashing attack (overwriting the function return address). Contiki-NG does not separate the MQTT server from other servers and the OS modules, so access to all memory regions is possible.

Affected products

contiki-ng: before 4.2 — fixed in 4.2

How to fix

Upgrade to a fixed version: contiki-ng 4.2. Check the vendor advisory for mitigations.

References

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