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Technical information leak - Logs

Description​

The application has an HTML file that displays a LOG of the system. In the event that this page is accessible by users, they will be able to know information about the system.

Impact​

Understand how the system works from the messages stored in the Log and generate an attack against the system based on this knowledge.

Recommendation​

Avoid exposing system information in files that can be accessed by third parties.

Threat​

External attacker from the Internet.

Expected Remediation Time​

⌚ 30 minutes.

Score​

Default score using CVSS 3.1. It may change depending on the context of the vulnerability.

Base​

  • Attack vector: L
  • Attack complexity: L
  • Privileges required: N
  • User interaction: N
  • Scope: U
  • Confidentiality: L
  • Integrity: N
  • Availability: N

Temporal​

  • Exploit code madurity: P
  • Remediation level: O
  • Report confidence: U

Result​

  • Vector string: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:P/RL:O/RC:U
  • Score:
    • Base: 4.0
    • Temporal: 3.3
  • Severity:
    • Base: Medium
    • Temporal: Low

Code Examples​

Compliant code​

Delete all logging functions in the production source code

Non compliant code​

The source code contains a file that could potentially display system logs

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script type="text/javascript">
    (function () {
      var old = system.log;
      var logger = document.getElementById('log');
      old = function (message) {
        if (typeof message == 'object') {
          logger.innerHTML += (JSON && JSON.stringify ? JSON.stringify(message) : message) + '<br />';
        } else {
          logger.innerHTML += message + '<br />';
        }
      }
    })();
  </script>
</body>
</html>

Requirements​

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