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.

Integer signedness error in libc/string/arm/memset.S in uClibc and uClibc-ng before 1.0.16 allows context-dependent attackers to cause a denial of service (crash) via a negative length value to the memset function.

In uClibc 0.9.33.2, there is an out-of-bounds read in the get_subexp function in misc/regex/regexec.c when processing a crafted regular expression.

In uClibc 0.9.33.2, there is stack exhaustion (uncontrolled recursion) in the check_dst_limits_calc_pos_1 function in misc/regex/regexec.c when processing a crafted regular expression.

A memory corruption vulnerability exists in the libpthread linuxthreads functionality of uClibC 0.9.33.2 and uClibC-ng 1.0.40. Thread allocation can lead to memory corruption. An attacker can create threads to trigger this vulnerability.

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.