From 3d27ee2e1c6df2289f3614807bcf9fe7bd2e1b3e Mon Sep 17 00:00:00 2001
From: "harshitha.d" <harshitha.d@contentstack.com>
Date: Wed, 19 Feb 2025 12:23:54 +0530
Subject: [PATCH] fix(attributes): sanitize keys and values to prevent html
 injection

---
 __test__/attributes-to-string.test.ts | 75 +++++++++++++++++++++++++++
 src/Models/metadata-model.ts          | 42 ++++++++-------
 src/helper/enumerate-entries.ts       |  9 ++--
 3 files changed, 103 insertions(+), 23 deletions(-)

diff --git a/__test__/attributes-to-string.test.ts b/__test__/attributes-to-string.test.ts
index 4b8173a..ca64f53 100644
--- a/__test__/attributes-to-string.test.ts
+++ b/__test__/attributes-to-string.test.ts
@@ -49,5 +49,80 @@ describe('Attributes to String', () => {
         expect(resultString).toEqual(' style="text-align:left; " rows="4" cols="2" colWidths="250, 250"')
         done()
     })
+    it('Should rignore attributes with forbidden characters in keys and values', done => {
+        const attr = {
+            "style": {
+                "text-align": "left"
+            },
+            "rows": 4,
+            "cols": 2,
+            "colWidths": [250, 250],
+            "<ls": "\"></p><h1>test</h1><p class=\"",
+            "\"></p><h1>test</h1><p class=\"": 1
+        } as Attributes;
+
+        const resultString = attributeToString(attr);
+
+        expect(resultString).toEqual(' style=\"text-align:left; \" rows=\"4\" cols=\"2\" colWidths=\"250, 250\" &lt;ls=\"&quot;&gt;&lt;/p&gt;&lt;h1&gt;test&lt;/h1&gt;&lt;p class=&quot;\"')
+        done();
+    });
+    it('Should handle object attribute values correctly', done => {
+        const attr = {
+            "style": {
+                "color": "red",
+                "font-size": "14px"
+            }
+        } as Attributes;
+
+        const resultString = attributeToString(attr);
+
+        expect(resultString).toEqual(' style="color:red; font-size:14px; "');
+        done();
+    });
+    it('Should convert arrays into comma-separated values', done => {
+        const attr = {
+            "data-values": [10, 20, 30]
+        } as Attributes;
+
+        const resultString = attributeToString(attr);
+
+        expect(resultString).toEqual(' data-values="10, 20, 30"');
+        done();
+    });
+    it('Should handle special characters in values properly', done => {
+        const attr = {
+            "title": 'This & That > Those < Them "Quoted"',
+            "description": "Hello <script>alert(xss)</script>"
+        } as Attributes;
+
+        const resultString = attributeToString(attr);
+
+        expect(resultString).toEqual(' title="This &amp; That &gt; Those &lt; Them &quot;Quoted&quot;" description="Hello &lt;script&gt;alert(xss)&lt;/script&gt;"');
+        done();
+    });
+
+    it('Should handle mixed types of values properly', done => {
+        const attr = {
+            "rows": 5,
+            "isEnabled": true,
+            "ids": [101, 102],
+            "style": { "margin": "10px", "padding": "5px" }
+        } as Attributes;
+
+        const resultString = attributeToString(attr);
+
+        expect(resultString).toEqual(' rows="5" isEnabled="true" ids="101, 102" style="margin:10px; padding:5px; "');
+        done();
+    });
+    it('Should sanitize both keys and values to prevent HTML injection', done => {
+        const attr = {
+            "<script>alert('key')</script>": "test",
+            "safeKey": "<script>alert(xss)</script>"
+        } as Attributes;
+
+        const resultString = attributeToString(attr);
 
+        expect(resultString).toEqual(' safeKey="&lt;script&gt;alert(xss)&lt;/script&gt;"');
+        done();
+    });
 })
\ No newline at end of file
diff --git a/src/Models/metadata-model.ts b/src/Models/metadata-model.ts
index 8d8a354..dd95c3b 100644
--- a/src/Models/metadata-model.ts
+++ b/src/Models/metadata-model.ts
@@ -1,5 +1,7 @@
 import StyleType from '../embedded-types/style-type';
 import TextNode from '../nodes/text-node';
+import { replaceHtmlEntities, forbiddenAttrChars } from '../helper/enumerate-entries';
+
 export interface Metadata {
   text: string;
   attributes: Attributes;
@@ -58,30 +60,30 @@ export function attributeToString(attributes: Attributes): string {
   let result = '';
   for (const key in attributes) {
     if (Object.prototype.hasOwnProperty.call(attributes, key)) {
-      let element = attributes[key];
-      if (element instanceof Array) {
-        let elementString = '';
-        let isFirst = true;
-        element.forEach((value) => {
-          if (isFirst) {
-            elementString += `${value}`;
-            isFirst = false;
-          } else {
-            elementString += `, ${value}`;
-          }
-        });
-        element = elementString;
-      } else if (typeof element === 'object') {
+      // Sanitize the key to prevent HTML injection
+      const sanitizedKey = replaceHtmlEntities(key);
+
+      // Skip keys that contain forbidden characters (even after sanitization)
+      if (forbiddenAttrChars.some(char => sanitizedKey.includes(char))) {
+        continue;
+      }
+      let value = attributes[key];
+      if (Array.isArray(value)) {
+        value = value.join(', ');
+      } else if (typeof value === 'object') {
         let elementString = '';
-        for (const elementKey in element) {
-          if (Object.prototype.hasOwnProperty.call(element, elementKey)) {
-            const value = element[elementKey];
-            elementString += `${elementKey}:${value}; `;
+        for (const subKey in value) {
+          if (Object.prototype.hasOwnProperty.call(value, subKey)) {
+            const subValue = value[subKey];
+            if (subValue != null && subValue !== '') {
+              elementString += `${replaceHtmlEntities(subKey)}:${replaceHtmlEntities(String(subValue))}; `;
+            }
           }
         }
-        element = elementString;
+        value = elementString;
       }
-      result += ` ${key}="${element}"`;
+      // Sanitize the value to prevent HTML injection
+      result += ` ${sanitizedKey}="${replaceHtmlEntities(String(value))}"`;
     }
   }
   return result;
diff --git a/src/helper/enumerate-entries.ts b/src/helper/enumerate-entries.ts
index c23e5b6..d76df3b 100644
--- a/src/helper/enumerate-entries.ts
+++ b/src/helper/enumerate-entries.ts
@@ -42,7 +42,7 @@ export function enumerateContents(
 }
 
 export function textNodeToHTML(node: TextNode, renderOption: RenderOption): string {
-  let text = escapeHtml(node.text);
+  let text = replaceHtmlEntities(node.text);
   if (node.classname || node.id) {
     text = (renderOption[MarkType.CLASSNAME_OR_ID] as RenderMark)(text, node.classname, node.id);
   }
@@ -159,9 +159,12 @@ function nodeToHTML(
   }
 }
 
-function escapeHtml(text: string): string {
+export function replaceHtmlEntities(text: string): string {
   return text
     .replace(/&/g, '&amp;')
     .replace(/</g, '&lt;')
     .replace(/>/g, '&gt;')
-}
\ No newline at end of file
+    .replace(/"/g, '&quot;')
+}
+
+export const forbiddenAttrChars = ['"', "'", '>','<', '/', '='];
\ No newline at end of file