package/jszip: fix CVE-2021-23413

This affects the package jszip before 3.7.0. Crafting a new zip file
with filenames set to Object prototype values (e.g __proto__, toString,
etc) results in a returned object with a modified prototype instance.

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/jszip/0001-fix-Use-a-null-prototype-object-for-this-files.patch

@@ -0,0 +1,56 @@
+From 22357494f424178cb416cdb7d93b26dd4f824b36 Mon Sep 17 00:00:00 2001
+From: Michael Aquilina <michaelaquilina@gmail.com>
+Date: Mon, 14 Jun 2021 12:28:46 +0100
+Subject: [PATCH] fix: Use a null prototype object for this.files
+
+This approach is taken to prevent overriding object methods that would
+exist on a normal object Object.create({})
+
+[Retrieved from:
+https://github.com/Stuk/jszip/commit/22357494f424178cb416cdb7d93b26dd4f824b36]
+Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+---
+ lib/index.js  | 5 ++++-
+ lib/object.js | 6 +++---
+ 2 files changed, 7 insertions(+), 4 deletions(-)
+
+diff --git a/lib/index.js b/lib/index.js
+index b449877..b4c95ba 100644
+--- a/lib/index.js
++++ b/lib/index.js
+@@ -19,7 +19,10 @@ function JSZip() {
+     //   "folder/" : {...},
+     //   "folder/data.txt" : {...}
+     // }
+-    this.files = {};
++    // NOTE: we use a null prototype because we do not
++    // want filenames like "toString" coming from a zip file
++    // to overwrite methods and attributes in a normal Object.
++    this.files = Object.create(null);
+ 
+     this.comment = null;
+ 
+diff --git a/lib/object.js b/lib/object.js
+index 1c9d8e8..aec3db7 100644
+--- a/lib/object.js
++++ b/lib/object.js
+@@ -179,16 +179,16 @@ var out = {
+      */
+     forEach: function(cb) {
+         var filename, relativePath, file;
++        /* jshint ignore:start */
++        // ignore warning about unwanted properties because this.files is a null prototype object
+         for (filename in this.files) {
+-            if (!this.files.hasOwnProperty(filename)) {
+-                continue;
+-            }
+             file = this.files[filename];
+             relativePath = filename.slice(this.root.length, filename.length);
+             if (relativePath && filename.slice(0, this.root.length) === this.root) { // the file is in the current root
+                 cb(relativePath, file); // TODO reverse the parameters ? need to be clean AND consistent with the filter search fn...
+             }
+         }
++        /* jshint ignore:end */
+     },
+ 
+     /**

package/jszip/jszip.mk

@@ -9,6 +9,9 @@ JSZIP_SITE = $(call github,Stuk,jszip,v$(JSZIP_VERSION))
 JSZIP_LICENSE = MIT or GPL-3.0
 JSZIP_LICENSE_FILES = LICENSE.markdown
 
+# 0001-fix-Use-a-null-prototype-object-for-this-files.patch
+JSZIP_IGNORE_CVES += CVE-2021-23413
+
 define JSZIP_INSTALL_TARGET_CMDS
 	$(INSTALL) -m 0644 -D $(@D)/dist/jszip.min.js \
 		$(TARGET_DIR)/var/www/jszip/js/jszip.min.js