Quantum Secular Labs / Blog / Advisories
CVE-2018-19417: Contiki Ng: Remote code execution
CVE-2018-19417 is rated critical with a CVSS v3.0 base score of 10.0 and affects Contiki Ng. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.
Vulnerability 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.
Severity breakdown
CVSS v3.0 10.0: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
- Attack complexity: Low. No special conditions; the attack can be repeated reliably.
- Privileges required: None. No account or prior access is needed.
- User interaction: None. No action from any user is needed.
- Scope: Changed. Impact reaches beyond the vulnerable component to other resources.
- Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
- Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
- Availability impact: High. Total loss of availability; the component can be shut down.
Underlying weakness
CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary.
Affected products
- Contiki Ng: before 4.2