Description

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.

Severity HIGH

CVSS Score 7.3

CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

CWE CWE-918

Public Exploit ⚠️ Yes

Source NVD

Published 2024-02-07

Updated 2026-06-02

Modified 2024-11-21

Fix URL https://github.com/libuv/libuv/commit/0f2d7e784a256b54b2385043438848047bc2a629

Software	From version	Fixed in
libuv	1.24.0	1.48.0