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add sending output format strings and templates lab #503

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125 changes: 125 additions & 0 deletions docs/labs/sending_output.html
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<!DOCTYPE html>
<html><script src="template_files/page-script.js" id="bw-fido2-page-script"></script><head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="template_files/style.css">
<link rel="stylesheet" href="template_files/checker.css">
<script src="template_files/js-yaml.min.js"></script>
<script src="template_files/checker.js"></script>
<link rel="license" href="https://creativecommons.org/licenses/by/4.0/">

<!-- See create_labs.md for how to create your own lab! -->

<!-- Sample expected answer -->
<script id="expected0" type="plain/text">
private final List<String> allowedHosts = new String[]{"127.0.0.1"}
</script>
<!--
-->
<script id="expected1" type="plain/text">
private final List<String> allowedHosts = new String[]{"localhost"}
</script>

<!-- Full pattern of correct answer -->
<script id="correct0" type="plain/text">
private final List<String> allowedHosts = new String\[]{"(127\.0\.0\.1|localhost)"}
</script>

<script id="correct1" type="plain/text">
private final List<String> allowedHosts = new String\[]{"127\.0\.0\.1",(\s)*"localhost"}
</script>

<script id="correct2" type="plain/text">
private final List<String> allowedHosts = new String\[]{"locahost",(\s)*"127\.0\.0\.1"}
</script>

<script id="info" type="application/yaml">
---
hints:
- present: "new String[]{}"
text: Add allowed hosts the string array enclosed in curly brackets.
- present: "private final List<String> allowedHosts ="
text: Make sure that the allowedHosts constant is an Java inline string array.
# debug: true
</script>
</head>
<body>
<!-- For GitHub Pages formatting: -->
<div class="container-lg px-3 my-5 markdown-body">
<h1>Format Strings and Templates Lab</h1>
<p>
This is a lab exercise on developing secure software.
For more information, see the <a href="https://best.openssf.org/labs/introduction.html" target="_blank">introduction to
the labs</a>.

</p><p>
</p><h2>Task</h2>
<p>
<b>Restrict the JNDI hostnames from which variables can be loaded.</b>

</p><p>
</p><h2>Background</h2>
<p>
In this exercise, we'll assume that out output template allows a user to specify a JNDI hostname
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@jasinner jasinner Jul 17, 2024 •
edited
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@david-a-wheeler What If we updated the Background section by adding:

"Allowing a user to load variables is still a security risk, even from the same host. However the program requirements might dictate it's necessary. We're going to assume that in this exercise it's required to load variables from a JNDI server on the same host, and disabling such functionality is not an option."

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That makes sense to me!

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However, it's not really dealing with the underlying issue I raised earlier.

from which to load variables from. As is the case in the Log4j logging framework.

</p><p>
</p><h2>Task Information</h2>
<p>

</p><p>
Please change the code below so that it restricts the JNDI hostnames from which variables can be
loaded to only the local network interface (127.0.0.1). Use IPv4 addresses only.


</p><p>
</p><h2>Interactive Lab (<span id="grade">to be completed</span>)</h2>
<p>
</p><form id="lab">
<pre><code>
public class JndiManager extends AbstractManager {
<input id="attempt0" type="text" size="60" spellcheck="false"
value="private final List<String> allowedHosts = new String[]{}" style="background-color: yellow;">

/**
* Looks up a named object through this JNDI context.
*
* @param name name of the object to look up.
* @param <T> the type of the object.
* @return the named object if it could be located.
* @throws NamingException if a naming exception is encountered
*/
@SuppressWarnings("unchecked")
public <T> T lookup(final String name) throws NamingException {
URI uri = new URI(name);
if (!allowedHosts.contains(uri.getHost())) {
LOGGER.warn("Attempt to access ldap server not in allowed list");
return null;
}
return (T) this.context.lookup(name);
}
}
</code></pre>
<button type="button" class="hintButton" title="Provide a hint given current attempt.">Hint</button>
<button type="button" class="resetButton" title="Reset initial state (throwing away current attempt).">Reset</button>
<button type="button" class="giveUpButton" title="Give up and show an answer.">Give up</button>
<br><br>
<p>
<i>This lab was developed by Jason Shepherd at
<a href="https://access.redhat.com/security/">Red Hat Product Security</a>.</i>
<br><br>
</p><p id="correctStamp" class="small">
<textarea id="debugData" class="displayNone" rows="20" cols="65" readonly="readonly"></textarea>
</p></form>
<br><br>
<p>
<summary>
Source: This example is a modified version of the patch for CVE-2021-44228 in
<a href="https://github.com/apache/logging-log4j2/pull/608/files">apache/logging-log4j2</a>
</summary>
</p>
</div><!-- End GitHub pages formatting -->


</body></html>