CVE-2024-24576: Rust Standard Library RCE Vulnerability

CVE-2024-24576 Overview

CVE-2024-24576 is a command injection vulnerability in the Rust standard library affecting versions prior to 1.77.2. The vulnerability exists in how the Rust standard library handles argument escaping when invoking batch files (.bat and .cmd extensions) on Windows using the Command API. An attacker who can control arguments passed to a spawned process could bypass the escaping mechanism and execute arbitrary shell commands.

The Command::arg and Command::args APIs in Rust are documented to pass arguments to spawned processes as-is without shell evaluation. However, on Windows, this implementation is complex because the Windows API only provides a single string containing all arguments, leaving it to the spawned process to split them. While most programs use the standard C run-time argv for consistent argument splitting, cmd.exe (used to execute batch files) implements its own argument splitting logic, which the standard library's escaping failed to properly handle.

Critical Impact

This vulnerability allows remote attackers to execute arbitrary shell commands on Windows systems when Rust applications invoke batch files with untrusted arguments, potentially leading to complete system compromise.

Affected Products

• Rust versions prior to 1.77.2
• Fedora 38, 39, and 40 (with vulnerable Rust packages)
• Microsoft Windows (as the affected platform)

Discovery Timeline

• April 9, 2024 - CVE-2024-24576 published to NVD
• January 5, 2026 - Last updated in NVD database

Technical Details for CVE-2024-24576

Vulnerability Analysis

This vulnerability represents a classic command injection (CWE-78) scenario stemming from insufficient input sanitization in a security-critical API. The Rust standard library provides the Command struct for spawning child processes, with Command::arg and Command::args methods that promise to pass arguments safely without shell interpretation. This API guarantee is critical because developers rely on it to safely handle untrusted input.

On Windows, the underlying process creation API (CreateProcess) receives all arguments as a single concatenated string. Each spawned program must parse this string to extract individual arguments. The standard C runtime (MSVCRT) provides consistent parsing behavior that most Windows programs follow. However, cmd.exe—the Windows command processor used to execute batch files—implements proprietary argument parsing with different escaping rules and special character handling.

The Rust standard library attempted to implement custom escaping logic to maintain its safety guarantees when spawning batch files. However, the escaping was incomplete, allowing crafted argument strings to break out of the intended context and inject arbitrary commands that cmd.exe would execute.

Root Cause

The root cause is the impedance mismatch between the Rust Command API's promise of safe argument passing and the complex, underdocumented argument parsing behavior of Windows cmd.exe. The standard library's escaping logic failed to account for all the edge cases and special characters that cmd.exe interprets, creating an exploitable gap between the documented behavior and actual execution.

Due to the complexity and inconsistency of cmd.exe argument parsing, the Rust team determined that no escaping solution could guarantee safety in all cases. The fix in version 1.77.2 improves escaping robustness but also changes the API to return an InvalidInput error when an argument cannot be safely escaped.

Attack Vector

The attack requires an attacker to control arguments that a Rust application passes to a batch file execution on Windows. This could occur in scenarios where:

• Web applications accept user input that is passed to batch file processes
• Command-line tools process untrusted filenames or parameters
• Applications integrate with Windows system utilities via batch scripts

When malicious arguments bypass the escaping logic, cmd.exe interprets them as additional commands, enabling arbitrary command execution with the privileges of the Rust application.

The vulnerability mechanism involves crafting argument strings that exploit cmd.exe's special character handling. When passed through the inadequate escaping logic, these strings can terminate the intended argument and inject arbitrary commands. For detailed technical analysis, refer to the GitHub Security Advisory GHSA-q455-m56c-85mh and the CERT Vulnerability ID 123335.

Detection Methods for CVE-2024-24576

Indicators of Compromise

• Unexpected batch file executions with unusual command-line arguments
• Child processes spawned from Rust applications executing cmd.exe with suspicious command chains
• Process creation events showing multiple commands chained with &, |, or other shell metacharacters in batch file arguments

Detection Strategies

• Monitor for Rust applications spawning cmd.exe or batch files with arguments containing shell metacharacters such as &, |, ^, <, >, and "
• Implement application-level logging to capture all arguments passed to Command APIs before process spawning
• Use endpoint detection to identify process trees where Rust executables spawn unexpected command interpreters

Monitoring Recommendations

• Enable Windows Process Creation auditing (Event ID 4688) with command-line logging to capture batch file invocations
• Deploy behavioral analysis rules to detect command injection patterns in process arguments
• Establish baselines for legitimate batch file usage in Rust applications and alert on deviations

How to Mitigate CVE-2024-24576

Immediate Actions Required

• Upgrade Rust to version 1.77.2 or later immediately on all Windows development and production systems
• Audit Rust applications that invoke batch files with external or user-controlled input
• Implement strict input validation for any arguments passed to batch file executions
• Consider replacing batch file invocations with direct executable calls where possible

Patch Information

The fix is included in Rust 1.77.2. The patch improves the robustness of the escaping code and modifies the Command API to return an InvalidInput error when it cannot safely escape an argument. This error is emitted when attempting to spawn the process.

Note that the new escaping logic is intentionally conservative and may reject some valid arguments. Developers who implement their own escaping or only handle trusted inputs can use the CommandExt::raw_arg method to bypass the standard library's escaping logic. Refer to the Rust CommandExt raw_arg documentation for details.

Fedora users should apply the security updates announced for Fedora 38, 39, and 40 through the Fedora Package Announcements.

Workarounds

• Avoid invoking batch files from Rust applications when processing untrusted input
• Use direct executable invocations instead of batch file wrappers where functionally equivalent
• Implement application-level argument sanitization that removes or rejects shell metacharacters before passing to Command APIs
• For applications requiring batch file functionality, consider sandboxing or running with reduced privileges

# Verify Rust version is patched
rustc --version
# Should show 1.77.2 or later

# Update Rust toolchain
rustup update stable

# For Fedora systems, update via dnf
sudo dnf update rust cargo