From 3d22fa5d2435de5acc18de6f88474a6e8675a60e Mon Sep 17 00:00:00 2001
From: Knut Sveidqvist <knut.sveidqvist@ipiccolo.com>
Date: Tue, 8 Jun 2021 20:08:04 +0200
Subject: [PATCH] =?UTF-8?q?2122=20Bl=C3=B6ockling=20javascript=20urls?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 cypress/integration/other/xss.spec.js |  5 ++
 cypress/platform/xss5.html            | 99 +++++++++++++++++++++++++++
 src/diagrams/common/common.js         |  4 ++
 3 files changed, 108 insertions(+)
 create mode 100644 cypress/platform/xss5.html
diff --git a/cypress/integration/other/xss.spec.js b/cypress/integration/other/xss.spec.js
index 830be4f8e..842eab36f 100644
--- a/cypress/integration/other/xss.spec.js
+++ b/cypress/integration/other/xss.spec.js
@@ -58,5 +58,10 @@ describe('XSS', () => {
     cy.wait(1000);
     cy.get('#the-malware').should('not.exist');
   })
+  it('should not allow maniplulating antiscript to run javascript', () => {
+    cy.visit('http://localhost:9000/xss5.html');
+    cy.wait(1000);
+    cy.get('#the-malware').should('not.exist');
+  })
 
 })
diff --git a/cypress/platform/xss5.html b/cypress/platform/xss5.html
new file mode 100644
index 000000000..9d3ad4da6
--- /dev/null
+++ b/cypress/platform/xss5.html
@@ -0,0 +1,99 @@
+<html>
+  <head>
+    <link
+      href="https://fonts.googleapis.com/css?family=Montserrat&display=swap"
+      rel="stylesheet"
+    />
+    <link href="https://unpkg.com/tailwindcss@^1.0/dist/tailwind.min.css" rel="stylesheet">
+    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
+    <link href="https://fonts.googleapis.com/css?family=Noto+Sans+SC&display=swap" rel="stylesheet">
+    <style>
+      body {
+        /* background: rgb(221, 208, 208); */
+        /* background:#333; */
+        font-family: 'Arial';
+        /* font-size: 18px !important; */
+        }
+      h1 { color: grey;}
+      .mermaid2 {
+        display: none;
+      }
+      .mermaid svg {
+        /* font-size: 18px !important; */
+      }
+      .malware {
+        position: fixed;
+        bottom:0;
+        left:0;
+        right:0;
+        height: 150px;
+        background: red;
+        color: black;
+        display: flex;
+        display: flex;
+        justify-content: center;
+        align-items: center;
+        font-family: monospace;
+        font-size: 72px;
+      }
+    </style>
+  </head>
+  <body>
+    <div>Security check</div>
+    <div class="flex">
+      <div id="diagram" class="mermaid"></div>
+      <div id="res" class=""></div>
+  <script src="./mermaid.js"></script>
+    <script>
+      mermaid.parseError = function (err, hash) {
+          // console.error('Mermaid error: ', err);
+        };
+      mermaid.initialize({
+        theme: 'forest',
+        arrowMarkerAbsolute: true,
+        // themeCSS: '.edgePath .path {stroke: red;} .arrowheadPath {fill: red;}',
+        logLevel: 0,
+        state: {
+          defaultRenderer: 'dagre-wrapper',
+        },
+        flowchart: {
+          // defaultRenderer: 'dagre-wrapper',
+          nodeSpacing: 10, curve: 'cardinal', htmlLabels: true
+        },
+        htmlLabels: true,
+        // gantt: { axisFormat: '%m/%d/%Y' },
+        sequence: { actorFontFamily: 'courier',actorMargin: 50, showSequenceNumbers: false },
+        // sequenceDiagram: { actorMargin: 300 } // deprecated
+        // fontFamily: '"times", sans-serif',
+        // fontFamily: 'courier',
+        fontSize: 18,
+        curve: 'basis',
+        securityLevel: 'antiscript',
+        startOnLoad: false,
+        secure: ['secure', 'securityLevel', 'startOnLoad', 'maxTextSize']
+        // themeVariables: {relationLabelColor: 'red'}
+      });
+      function callback(){alert('It worked');}
+      function xssAttack(){
+        const div = document.createElement('div')
+        div.id = 'the-malware'
+        div.className = 'malware'
+        div.innerHTML = 'XSS Succeeded'
+        document.getElementsByTagName('body')[0].appendChild(div);
+        throw new Error('XSS Succeded');
+      }
+      var diagram = "graph LR\n";
+  diagram += "B-->D\(\"<img onerror=location=\`java";
+  // diagram += "script\u003aalert\u0028document.domain\u0029\` src=x>\"\);\n";
+  diagram += "script\x3a;xssAttack\u0028\u0029\` src=x>\"\);\n";
+
+  console.log(diagram);
+  // document.querySelector('#diagram').innerHTML = diagram;
+  mermaid.render('diagram', diagram, (res) => {
+    console.log(res);
+    document.querySelector('#res').innerHTML = res;
+  });
+    </script>
+  </body>
+</html>
+
diff --git a/src/diagrams/common/common.js b/src/diagrams/common/common.js
index 4e26efca8..885f350de 100644
--- a/src/diagrams/common/common.js
+++ b/src/diagrams/common/common.js
@@ -26,6 +26,10 @@ export const removeScript = txt => {
       break;
     }
   }
+
+  rs = rs.replace('javascript:', '#');
+  rs = rs.replace('<iframe', '');
+
   return rs;
 };
 
