In Eclipse Mosquitto 1.5.0 to 1.6.5 inclusive, if a malicious MQTT client sends a SUBSCRIBE packet containing a topic that consists of approximately 65400 or more '/' characters, i.e. the topic hierarchy separator, then a stack overflow will occur.
| Software | From | Fixed in |
|---|---|---|
| eclipse / mosquitto | 1.6 | 1.6.6 |
| eclipse / mosquitto | 1.5 | 1.5.9 |
| canonical / ubuntu_linux | 19.04 | 19.04.x |
| opensuse / leap | 15.1 | 15.1.x |
| opensuse / backports_sle | 15.0-sp1 | 15.0-sp1.x |
| fedoraproject / fedora | 29 | 29.x |
| fedoraproject / fedora | 30 | 30.x |
| fedoraproject / fedora | 31 | 31.x |
| debian / debian_linux | 8.0 | 8.0.x |
| debian / debian_linux | 10.0 | 10.0.x |