CVE-2019-17210 Null dereference in n/a
An attacker can cause a denial of service in Arm Mbed OS by manipulating MQTT packet length fields to trigger a null pointer dereference.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2019-17210?
CVE-2019-17210 is a high-severity vulnerability in n/a, published on 4 Nov 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A denial-of-service issue was discovered in the MQTT library in Arm Mbed OS 2017-11-02. The function readMQTTLenString() is called by the function MQTTDeserialize_publish() to get the length and content of the MQTT topic name. In the function readMQTTLenString(), mqttstring->lenstring.len is a part of user input, which can be manipulated. An attacker can simply change it to a larger value to invalidate the if statement so that the statements inside the if statement are skipped, letting the value of mqttstring->lenstring.data default to zero. Later, curn is accessed, which points to mqttstring->lenstring.data. On an Arm Cortex-M chip, the value at address 0x0 is actually the initialization value for the MSP register. It is highly dependent on the actual firmware. Therefore, the behavior of the program is unpredictable from this time on.
Weakness: CWE-20
Which versions are affected by CVE-2019-17210?
It affects 2 products.
Products include Arm Mbed-Mqtt, Arm Mbed-Os.
How do I fix CVE-2019-17210?
No fix has been published for CVE-2019-17210 yet. Limit exposure of the affected software until one is available.
Is CVE-2019-17210 being exploited?
There is no known exploitation of CVE-2019-17210 in the wild and no public exploit code.
Sources
Also known as GHSA-xp54-622x-6x77.