In tinysvcmdns through 2018-01-16, an mDNS server processing a crafted packet can perform arbitrary data read operations up to 16383 bytes from the start of the buffer. This can lead to a segmentation fault in uncompress_nlabel in mdns.c and a crash of the server (depending on the memory protection of the CPU and the operating system), or disclosure of memory content via error messages or a server response. NOTE: the product's web site states "This project is un-maintained, and has been since 2013. ... There are known vulnerabilities ... You are advised to NOT use this library for any new projects / products."

In tinysvcmdns through 2018-01-16, a maliciously crafted mDNS (Multicast DNS) packet triggers an infinite loop while parsing an mDNS query. When mDNS compressed labels point to each other, the function uncompress_nlabel goes into an infinite loop trying to analyze the packet with an mDNS query. As a result, the mDNS server hangs after receiving the malicious mDNS packet. NOTE: the product's web site states "This project is un-maintained, and has been since 2013. ... There are known vulnerabilities ... You are advised to NOT use this library for any new projects / products."

An exploitable heap overflow vulnerability exists in the tinysvcmdns library version 2016-07-18. A specially crafted packet can make the library overwrite an arbitrary amount of data on the heap with attacker controlled values. An attacker needs send a dns packet to trigger this vulnerability.

An exploitable NULL pointer dereference vulnerability exists in the tinysvcmdns library version 2017-11-05. A specially crafted packet can make the library dereference a NULL pointer leading to a server crash and denial of service. An attacker needs to send a DNS query to trigger this vulnerability.