Fix for CVE-2020-14343

Per suggestion #420 (comment) move a few constructors from full_load to unsafe_load.
yaml · Jan 9, 2021 · 7adc0db · 7adc0db
1 parent f41c722
commit 7adc0db
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Showing 4 changed files with 26 additions and 26 deletions.
diff --git a/lib/yaml/constructor.py b/lib/yaml/constructor.py
@@ -722,18 +722,6 @@ def construct_python_object_new(self, suffix, node):
     u'tag:yaml.org,2002:python/name:',
     FullConstructor.construct_python_name)
 
-FullConstructor.add_multi_constructor(
-    u'tag:yaml.org,2002:python/module:',
-    FullConstructor.construct_python_module)
-
-FullConstructor.add_multi_constructor(
-    u'tag:yaml.org,2002:python/object:',
-    FullConstructor.construct_python_object)
-
-FullConstructor.add_multi_constructor(
-    u'tag:yaml.org,2002:python/object/new:',
-    FullConstructor.construct_python_object_new)
-
 class UnsafeConstructor(FullConstructor):
 
     def find_python_module(self, name, mark):
@@ -750,6 +738,18 @@ def set_python_instance_state(self, instance, state):
         return super(UnsafeConstructor, self).set_python_instance_state(
             instance, state, unsafe=True)
 
+UnsafeConstructor.add_multi_constructor(
+    u'tag:yaml.org,2002:python/module:',
+    UnsafeConstructor.construct_python_module)
+
+UnsafeConstructor.add_multi_constructor(
+    u'tag:yaml.org,2002:python/object:',
+    UnsafeConstructor.construct_python_object)
+
+UnsafeConstructor.add_multi_constructor(
+    u'tag:yaml.org,2002:python/object/new:',
+    UnsafeConstructor.construct_python_object_new)
+
 UnsafeConstructor.add_multi_constructor(
     u'tag:yaml.org,2002:python/object/apply:',
     UnsafeConstructor.construct_python_object_apply)

diff --git a/lib3/yaml/constructor.py b/lib3/yaml/constructor.py
@@ -710,18 +710,6 @@ def construct_python_object_new(self, suffix, node):
     'tag:yaml.org,2002:python/name:',
     FullConstructor.construct_python_name)
 
-FullConstructor.add_multi_constructor(
-    'tag:yaml.org,2002:python/module:',
-    FullConstructor.construct_python_module)
-
-FullConstructor.add_multi_constructor(
-    'tag:yaml.org,2002:python/object:',
-    FullConstructor.construct_python_object)
-
-FullConstructor.add_multi_constructor(
-    'tag:yaml.org,2002:python/object/new:',
-    FullConstructor.construct_python_object_new)
-
 class UnsafeConstructor(FullConstructor):
 
     def find_python_module(self, name, mark):
@@ -738,6 +726,18 @@ def set_python_instance_state(self, instance, state):
         return super(UnsafeConstructor, self).set_python_instance_state(
             instance, state, unsafe=True)
 
+UnsafeConstructor.add_multi_constructor(
+    'tag:yaml.org,2002:python/module:',
+    UnsafeConstructor.construct_python_module)
+
+UnsafeConstructor.add_multi_constructor(
+    'tag:yaml.org,2002:python/object:',
+    UnsafeConstructor.construct_python_object)
+
+UnsafeConstructor.add_multi_constructor(
+    'tag:yaml.org,2002:python/object/new:',
+    UnsafeConstructor.construct_python_object_new)
+
 UnsafeConstructor.add_multi_constructor(
     'tag:yaml.org,2002:python/object/apply:',
     UnsafeConstructor.construct_python_object_apply)

diff --git a/tests/lib/test_recursive.py b/tests/lib/test_recursive.py
@@ -30,7 +30,7 @@ def test_recursive(recursive_filename, verbose=False):
     output2 = None
     try:
         output1 = yaml.dump(value1)
-        value2 = yaml.load(output1, yaml.FullLoader)
+        value2 = yaml.load(output1, yaml.UnsafeLoader)
         output2 = yaml.dump(value2)
         assert output1 == output2, (output1, output2)
     finally:

diff --git a/tests/lib3/test_recursive.py b/tests/lib3/test_recursive.py
@@ -31,7 +31,7 @@ def test_recursive(recursive_filename, verbose=False):
     output2 = None
     try:
         output1 = yaml.dump(value1)
-        value2 = yaml.full_load(output1)
+        value2 = yaml.unsafe_load(output1)
         output2 = yaml.dump(value2)
         assert output1 == output2, (output1, output2)
     finally: