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GHSA-27m7-ffhq-jqrm
No affected components available
Summary
The MCPScanner class contains a critical Command Injection vulnerability in the cloneRepo method. The application passes the user-supplied githubUrl argument directly to a system shell via execSync without sanitization. This allows an attacker to execute arbitrary commands on the host machine by appending shell metacharacters to the URL.
Details
The vulnerability exists in the src/scanner/MCPScanner.ts file within the cloneRepo method.
The code uses child_process.execSync to execute a git clone command:
Because execSync spawns a shell (defaulting to /bin/sh on Unix or cmd.exe on Windows), any shell metacharacters present in the url argument will be interpreted by the shell. The application does not validate that the url is a valid Git URL, nor does it sanitize input for shell metacharacters.
PoC
Install the package or clone the repository.
Run the scanner using the CLI (or invoke scanRepository programmatically).
Provide a malicious URL containing a command separator (e.g., ;, &, or |) and a system command.
payload : npm run scan:github "https://github.com/kapilduraphe/mcp-watch & calc.exe"
Impact
Severity: Critical
CVSS Score: 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) Description: This vulnerability allows an attacker to execute arbitrary code on the machine running the scanner.
If run by a developer locally, it compromises their workstation.
If deployed as a hosted scanning service, it grants the attacker full control over the server (RCE), leading to potential data exfiltration, service disruption, or further lateral movement within the infrastructure.
Context Dependent Risk:
Local CLI : If you run this tool locally on your own machine, you are "hacking yourself." The risk is limited unless you copy-paste a malicious URL sent by someone else (e.g., "Hey, check this repo scan: npm run scan "https://git./..; rm -rf /").
Web Service / CI Pipeline (Critical Risk): If this scanner is deployed as a web service (e.g., "Paste your repo URL to scan"), an attacker can take full control of the server immediately.
The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a high impact on the confidentiality of the information. There is a high impact on the integrity of the data. There is a high impact on the availability of the system.
Active exploitation in the wild has been confirmed. Immediate patching or mitigation is required.
Probability that this vulnerability will be exploited in the wild within the next 30 days.
We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.
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