Content Injection Affecting Crow package, versions [,0.3+4)


Severity

Recommended
0.0
medium
0
10

CVSS assessment made by Snyk's Security Team

    Threat Intelligence

    EPSS
    0.08% (35th percentile)

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  • Snyk ID SNYK-UNMANAGED-CROW-2336164
  • published 12 Jan 2022
  • disclosed 12 Jan 2022
  • credit Snyk Security Team

How to fix?

Upgrade Crow to version 0.3+4 or higher.

Overview

Crow is a C++ microframework for running web services.

Affected versions of this package are vulnerable to Content Injection. When using attributes without quotes in the template, an attacker can manipulate the input to introduce additional attributes, potentially executing code. This may lead to a Cross-site Scripting (XSS) vulnerability, assuming an attacker can influence the value entered into the template. If the template is used to render user-generated content, this vulnerability may escalate to a persistent XSS vulnerability.

PoC

templates/test.html file:

<html><body><img src={{src}} /></body></html>

main.cpp file:

#include "crow.h"
int main()
{
    crow::SimpleApp app;
    CROW_ROUTE(app, "/")([](const crow::request& req){
        crow::mustache::context x;
        x["src"] = req.url_params.get("src");
        auto page = crow::mustache::load("test.html");
        return page.render(x);
    });
    app.port(8888).run();
}

The malicious payload: http://localhost:8888/?src=x%20onerror%3Dalert(1)

CVSS Scores

version 3.1
Expand this section

Snyk

6.5 medium
  • Attack Vector (AV)
    Network
  • Attack Complexity (AC)
    Low
  • Privileges Required (PR)
    None
  • User Interaction (UI)
    None
  • Scope (S)
    Unchanged
  • Confidentiality (C)
    Low
  • Integrity (I)
    Low
  • Availability (A)
    None
Expand this section

NVD

6.1 medium