libuv is a multi-platform support library with a focus on asynchronous I/O. The `uv_getaddrinfo` function in `src/unix/getaddrinfo.c` (and its windows counterpart `src/win/getaddrinfo.c`), truncates hostnames to 256 characters before calling `getaddrinfo`. This behavior can be exploited to create addresses like `0x00007f000001`, which are considered valid by `getaddrinfo` and could allow an attacker to craft payloads that resolve to unintended IP addresses, bypassing developer checks. The vulnerability arises due to how the `hostname_ascii` variable (with a length of 256 bytes) is handled in `uv_getaddrinfo` and subsequently in `uv__idna_toascii`. When the hostname exceeds 256 characters, it gets truncated without a terminating null byte. As a result attackers may be able to access internal APIs or for websites (similar to MySpace) that allows users to have `username.example.com` pages. Internal services that crawl or cache these user pages can be exposed to SSRF attacks if a malicious user chooses a long vulnerable username. This issue has been addressed in release version 1.48.0. Users are advised to upgrade. There are no known workarounds for this vulnerability.

libuv

The implementation of realpath in libuv < 10.22.1, < 12.18.4, and < 14.9.0 used within Node.js incorrectly determined the buffer size which can result in a buffer overflow if the resolved path is longer than 256 bytes.

nodejs · opensuse · fedoraproject

The uv_rwlock_t fallback implementation for Windows XP and Server 2003 in libuv before 1.7.4 does not properly prevent threads from releasing the locks of other threads, which allows attackers to cause a denial of service (deadlock) or possibly have unspecified other impact by leveraging a race condition.

libuv · microsoft · nodejs

libuv before 0.10.34 does not properly drop group privileges, which allows context-dependent attackers to gain privileges via unspecified vectors.

fedoraproject · libuv_project · nodejs