CVE-2023-53158 in gix-transport Crate
Summary
by MITRE • 07/28/2025
The gix-transport crate before 0.36.1 for Rust allows command execution via the "gix clone 'ssh://-oProxyCommand=open$IFS" substring. NOTE: this was discovered before CVE-2024-32884, a similar vulnerability (involving a username field) that is more difficult to exploit.
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Analysis
by VulDB Data Team • 08/19/2025
The CVE-2023-53158 vulnerability affects the gix-transport crate version 0.36.0 and earlier, representing a critical command injection flaw that enables arbitrary code execution through SSH transport operations. This vulnerability specifically manifests when processing SSH URLs containing malicious proxy command directives, creating a pathway for attackers to execute arbitrary commands on systems that utilize this crate for Git operations. The flaw exists in how the crate handles SSH connection parameters, particularly when parsing URL components that include proxy command specifications, making it a significant concern for development environments and CI/CD pipelines that rely on Git operations.
The technical implementation of this vulnerability stems from inadequate input validation and sanitization within the SSH transport layer of the gix-transport crate. When a Git clone operation is initiated with an SSH URL containing the malicious pattern "ssh://-oProxyCommand=open$IFS", the crate fails to properly escape or validate the SSH options passed to underlying SSH clients. This allows the attacker to inject additional SSH configuration options that can execute arbitrary commands on the target system. The vulnerability is particularly dangerous because it leverages the standard SSH proxy command functionality, which is designed to enable complex network routing but becomes exploitable when misused through crafted input. The $IFS variable in the payload serves to bypass certain input filters by creating word splitting behavior that can be exploited in shell contexts.
The operational impact of this vulnerability extends beyond simple command execution, as it can lead to complete system compromise when exploited in environments where Git operations are performed with elevated privileges. Attackers can leverage this vulnerability to execute arbitrary commands with the privileges of the user running the Git operations, potentially leading to data exfiltration, system persistence, or further network exploitation. This vulnerability is particularly concerning in automated build systems, continuous integration pipelines, and development environments where Git operations are performed automatically without proper input validation. The vulnerability can be exploited remotely through malicious Git repositories or by compromising systems that fetch code from untrusted sources, making it a significant threat to software supply chain security.
The mitigation strategy for CVE-2023-53158 requires immediate upgrading to gix-transport version 0.36.1 or later, which includes proper input validation and sanitization for SSH options. Organizations should also implement additional security measures such as restricting Git operations to trusted repositories, implementing network-level controls to prevent access to untrusted Git servers, and monitoring for suspicious Git operations that might indicate exploitation attempts. The vulnerability aligns with CWE-78, which describes improper neutralization of special elements used in OS commands, and can be mapped to ATT&CK technique T1059.001 for command and scripting interpreter. Organizations should also consider implementing runtime protections such as sandboxing Git operations, using containerized environments for Git activities, and establishing strict input validation policies for all external code repositories that might be accessed through Git operations. The vulnerability demonstrates the importance of proper input sanitization in security-critical components and serves as a reminder of the potential for command injection flaws in seemingly benign network protocols.