uClibc-ng through 1.0.40 and uClibc through 0.9.33.2 use predictable DNS transaction IDs that may lead to DNS cache poisoning. This is related to a reset of a value to 0x2.

uClibc-ng versions prior to 1.0.37 are vulnerable to integer wrap-around in functions malloc-simple. This improper memory assignment can lead to arbitrary memory allocation, resulting in unexpected behavior such as a crash or a remote code injection/execution.

In uClibc and uClibc-ng before 1.0.39, incorrect handling of special characters in domain names returned by DNS servers via gethostbyname, getaddrinfo, gethostbyaddr, and getnameinfo can lead to output of wrong hostnames (leading to domain hijacking) or injection into applications (leading to remote code execution, XSS, applications crashes, etc.). In other words, a validation step, which is expected in any stub resolver, does not occur.