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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2019-11779
• https://bugs.eclipse.org/bugs/show_bug.cgi?id=551160
• https://lists.debian.org/debian-lts-announce/2019/10/msg00035.html
• https://lists.fedoraproject.org/archives/list/[email protected]/message/D4WMHIM64Q35NGTR6R3ILZUL4MA4ANB5/
• https://lists.fedoraproject.org/archives/list/[email protected]/message/HFWQBNFTAVHPUYNGYO2TCPF5PCSWC2Z7/
• https://lists.fedoraproject.org/archives/list/[email protected]/message/JWNVTFA2CKXERXRYPYE2YFTZP4GNBGYY/
• https://seclists.org/bugtraq/2019/Nov/25
• https://usn.ubuntu.com/4137-1/
• https://www.debian.org/security/2019/dsa-4570
• http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00077.html
• http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00008.html