Xiaoxia AI
107 lines
2.8 KiB
Python
107 lines
2.8 KiB
Python
#
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# Copyright 2014 Hewlett-Packard Development Company, L.P.
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#
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# SPDX-License-Identifier: Apache-2.0
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r"""
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=========================================
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B110: Test for a pass in the except block
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=========================================
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Errors in Python code bases are typically communicated using ``Exceptions``.
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An exception object is 'raised' in the event of an error and can be 'caught' at
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a later point in the program, typically some error handling or logging action
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will then be performed.
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However, it is possible to catch an exception and silently ignore it. This is
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illustrated with the following example
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.. code-block:: python
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try:
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do_some_stuff()
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except Exception:
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pass
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This pattern is considered bad practice in general, but also represents a
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potential security issue. A larger than normal volume of errors from a service
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can indicate an attempt is being made to disrupt or interfere with it. Thus
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errors should, at the very least, be logged.
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There are rare situations where it is desirable to suppress errors, but this is
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typically done with specific exception types, rather than the base Exception
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class (or no type). To accommodate this, the test may be configured to ignore
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'try, except, pass' where the exception is typed. For example, the following
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would not generate a warning if the configuration option
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``checked_typed_exception`` is set to False:
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.. code-block:: python
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try:
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do_some_stuff()
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except ZeroDivisionError:
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pass
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**Config Options:**
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.. code-block:: yaml
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try_except_pass:
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check_typed_exception: True
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:Example:
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.. code-block:: none
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>> Issue: Try, Except, Pass detected.
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Severity: Low Confidence: High
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CWE: CWE-703 (https://cwe.mitre.org/data/definitions/703.html)
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Location: ./examples/try_except_pass.py:4
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3 a = 1
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4 except:
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5 pass
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.. seealso::
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- https://security.openstack.org
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- https://cwe.mitre.org/data/definitions/703.html
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.. versionadded:: 0.13.0
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.. versionchanged:: 1.7.3
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CWE information added
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"""
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import ast
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import bandit
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from bandit.core import issue
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from bandit.core import test_properties as test
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def gen_config(name):
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if name == "try_except_pass":
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return {"check_typed_exception": False}
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@test.takes_config
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@test.checks("ExceptHandler")
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@test.test_id("B110")
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def try_except_pass(context, config):
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node = context.node
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if len(node.body) == 1:
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if (
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not config["check_typed_exception"]
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and node.type is not None
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and getattr(node.type, "id", None) != "Exception"
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):
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return
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if isinstance(node.body[0], ast.Pass):
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return bandit.Issue(
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severity=bandit.LOW,
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confidence=bandit.HIGH,
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cwe=issue.Cwe.IMPROPER_CHECK_OF_EXCEPT_COND,
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text=("Try, Except, Pass detected."),
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)
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