Rust is a programming language. The fix for CVE-2024-24576, where `std::process::Command` incorrectly escaped arguments when invoking batch files on Windows, was incomplete. Prior to Rust version 1.81.0, it was possible to bypass the fix when the batch file name had trailing whitespace or periods (which are ignored and stripped by Windows). To determine whether to apply the `cmd.exe` escaping rules, the original fix for the vulnerability checked whether the command name ended with `.bat` or `.cmd`. At the time that seemed enough, as we refuse to invoke batch scripts with no file extension. Windows removes trailing whitespace and periods when parsing file paths. For example, `.bat. .` is interpreted by Windows as `.bat`, but the original fix didn't check for that. Affected users who are using Rust 1.77.2 or greater can remove the trailing whitespace (ASCII 0x20) and trailing periods (ASCII 0x2E) from the batch file name to bypass the incomplete fix and enable the mitigations. Users are…

Rust is a programming language. The Rust Security Response WG was notified that the Rust standard library prior to version 1.77.2 did not properly escape arguments when invoking batch files (with the `bat` and `cmd` extensions) on Windows using the `Command`. An attacker able to control the arguments passed to the spawned process could execute arbitrary shell commands by bypassing the escaping. The severity of this vulnerability is critical for those who invoke batch files on Windows with untrusted arguments. No other platform or use is affected. The `Command::arg` and `Command::args` APIs state in their documentation that the arguments will be passed to the spawned process as-is, regardless of the content of the arguments, and will not be evaluated by a shell. This means it should be safe to pass untrusted input as an argument. On Windows, the implementation of this is more complex than other platforms, because the Windows API only provides a single string containing all the argume…