Off-by-One Out-of-Bounds Vulnerability in Rsync by Rsync Project

CVE-2026-45232

What is CVE-2026-45232?

Rsync versions prior to 3.4.3 have a flaw in the establish_proxy_connection() function found in socket.c, which could allow network attackers to manipulate stack memory. By exploiting this vulnerability, attackers can insert themselves between the client and the proxy, or control the proxy server to send a malformed HTTP response line containing 1023 or more bytes without a newline terminator. This results in a null byte being written to an out-of-bounds stack address when the RSYNC_PROXY environment variable is active. It is crucial for users to update to version 3.4.3 or later to mitigate potential risks associated with this vulnerability.

References