diff --git a/CWE-664/CWE-400/README.md b/CWE-664/CWE-400/README.md new file mode 100644 index 0000000..9b98694 --- /dev/null +++ b/CWE-664/CWE-400/README.md @@ -0,0 +1,105 @@ +# CWE-400: Uncontrolled Resource Consumption +Canceling the task in a thread pool only prevents it from being executed if it has not started yet. For the task to be interruptible, it must handle the `threading.Event` flag. + +## Non-Compliant Code Example +Tasks can be submitted to the ThreadPoolExecutor by calling `submit()`. Submitted tasks can be canceled by calling `cancel()` on the Future object returned by `submit()`. Calling this method will return True and stop the task from being executed if it has not started yet. However, if its execution has already started, calling `cancel()` will instead return False and will not stop the task [Python 3.10 docs on Future.cancel]. + +[*noncompliant01.py:*](noncompliant01.py) + +```py +""" Non-compliant Code Example """ +import time +from concurrent.futures import ThreadPoolExecutor + + +def take_time(x): + print(f"Started Task: {x}") + # Simulate work + for i in range(10): + time.sleep(1) + print(f"Completed Task: {x}") + + +def run_thread(_executor, var): + future = _executor.submit(take_time, var) + return future + + +def interrupt(future): + print(future.cancel()) + print(f"Interrupted: {future}") + + +##################### +# Exploiting above code example +##################### + + +with ThreadPoolExecutor() as executor: + task = run_thread(executor, "A") + interrupt(task) + +``` + +## Compliant Solution + +Tasks submitted to the ThreadPoolExecutor can be interrupted by setting a thread-safe flag, such as `threading.Event` [Python 3.10 docs on threading.Event]. An Event object should be passed as an argument to the submitted task. From within the task function, we need to manually check the flag status by calling `event.is_set()` and handling the interruption. In order to set the Event flag, we can call `event.set()` on the event object. + +[*compliant01.py:*](compliant01.py) + +```py +""" Compliant Code Example """ +import time +from concurrent.futures import ThreadPoolExecutor +from threading import Event + + +def take_time(x, _event): + print(f"Started Task: {x}") + # Simulate work + for _ in range(10): + if _event.is_set(): + print(f"Interrupted Task: {x}") + # Save partial results + return + time.sleep(1) + print(f"Completed Task: {x}") + + +def run_thread(_executor, var): + e = Event() + future = _executor.submit(take_time, var, e) + return future, e + + +def interrupt(future, e): + """Cancel the task, just in case it is not yet running, and set the Event flag""" + future.cancel() + e.set() + + +##################### +# Exploiting above code example +##################### + + +with ThreadPoolExecutor() as executor: + task, event = run_thread(executor, "A") + interrupt(task, event) + +``` + +## Related Guidelines + +||| +|:---|:---| +|[MITRE CWE](http://cwe.mitre.org/)|Pillar [CWE-664: Improper Control of a Resource Through its Lifetime (4.13) (mitre.org)](https://cwe.mitre.org/data/definitions/664.html)| +|[MITRE CWE](http://cwe.mitre.org/)|Class [CWE-400: Uncontrolled Resource Consumption (4.12)](https://cwe.mitre.org/data/definitions/400.html)| +|[SEI CERT Coding Standard for Java](https://wiki.sei.cmu.edu/confluence/display/java/SEI+CERT+Oracle+Coding+Standard+for+Java)|[TPS02-J. Ensure that tasks submitted to a thread pool are interruptible](https://wiki.sei.cmu.edu/confluence/display/java/TPS02-J.+Ensure+that+tasks+submitted+to+a+thread+pool+are+interruptible)| + +## Biblography + +||| +|:---|:---| +|[[Python 3.10.4 docs Future.cancel]](https://docs.python.org/)|[concurrent.futures — Launching parallel tasks — Python 3.10.4 documentation](https://docs.python.org/3/library/concurrent.futures.html)| +|[[Python 3.10.4 docs on threading.Event]](https://docs.python.org/)|[threading — Thread-based parallelism - Event Objects](https://docs.python.org/3/library/threading.html#event-objects)| diff --git a/README.md b/README.md index 3ff923f..0d7dec2 100644 --- a/README.md +++ b/README.md @@ -8,25 +8,28 @@ This page is in initiative by Ericsson to improve secure coding in Python by pro Common Weakness Enamurator (CWE) [Pillar Weakness](https://cwe.mitre.org/documents/glossary/#Pillar%20Weakness) [mitre.org 2023]. It currently contains *only* the code examples, documentation will follow. -# Disclaimer +## Disclaimer + Content comes WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, as stated in the license text [CC-BY-4.0](LICENSE/CC-BY-4.0.txt) for documentation and [MIT](LICENSE/MIT.txt). Following or using the documentation and or code is at your own risk. Code examples are intended purely for educational use and not for products in parts or in full. Code examples are NOT to be used to cause harm of any kind to anyone or anything. +## Introduction -# Introduction Every person writing code shall study the following: * OWASP Secure Coding [Practices-Quick Reference Guide](https://owasp.org/www-project-secure-coding-practices-quick-reference-guide/) [OWASP 2022] * OWASP Top 10 Report [OWASP 2022](https://owasp.org/www-project-top-ten/) [OWASP 2022] * CWE Top 25 2022 [CWE 2022](https://cwe.mitre.org/top25/archive/2022/2022_cwe_top25.html) [MITRE 2023] -# Secure Coding Standard for Python +## Secure Coding Standard for Python + Code examples are written to explain security design with as little code as possible demonstrating the issue in the `noncompliantXX.py` titled Python file. The `compliantXX.py` file demonstrates only the mitigation or removal of the described risk. None of the code examples are intendet to be used 'as is' for production. Using the code is at your own risk. It is **not production code** and requires code-style or python best practices to be added such as: + * Inline documentation * Custom exceptions * Full descriptive variable names @@ -36,9 +39,9 @@ It is **not production code** and requires code-style or python best practices t |[CWE-664: Improper Control of a Resource Through its Lifetime](https://cwe.mitre.org/data/definitions/664.html)|Prominent CVE| |:-----------------------------------------------------------------------------------------------------------------------------------------------|:----| -|[CWE-134: Use of Externally-Controlled Format String](CWE-664/CWE-134/.)|[CVE-2022-27177](https://www.cvedetails.com/cve/CVE-2022-27177/),
CVSSv3.1: **9.8**,
EPSS:**00.37**(01.12.2023)| +|[CWE-134: Use of Externally-Controlled Format String](CWE-664/CWE-134/.)|[CVE-2022-27177](https://www.cvedetails.com/cve/CVE-2022-27177/),
CVSSv3.1: **9.8**,
EPSS:**00.37**(01.12.2023)| |[CWE-197: Numeric Truncation Error](CWE-664/CWE-197/.)|| -|[CWE-400: Uncontrolled Resource Consumption](CWE-664/CWE-400/.)|| +|[CWE-400: Uncontrolled Resource Consumption](CWE-664/CWE-400/README.md)|| |[CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)](CWE-664/CWE-409/.)|| |[CWE-410: Insufficient Resource Pool](CWE-664/CWE-410/.)|| |[CWE-502: Deserialization of Untrusted Data)](CWE-664/CWE-502/.)|| @@ -48,7 +51,6 @@ It is **not production code** and requires code-style or python best practices t |[XXX-005: Consider hash-based integrity verification of byte code files against their source code files](CWE-664/XXX-005/.)|| ||| - |[CWE-682: Incorrect Calculation](https://cwe.mitre.org/data/definitions/682.html)|Prominent CVE| |:---------------------------------------------------------------------------------------------------------------|:----| |[CWE-1335: Promote readability and compatibility by using mathematical written code with arithmetic operations instead of bit-wise operations](CWE-682/CWE-1335/.)|| @@ -71,7 +73,7 @@ It is **not production code** and requires code-style or python best practices t |[CWE-707: Improper Neutralization](https://cwe.mitre.org/data/definitions/707.html)|Prominent CVE| |:----------------------------------------------------------------|:----| -|[CWE-89: Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')](CWE-707/CWE-89/.)|[CVE-2019-8600](https://www.cvedetails.com/cve/CVE-2019-8600/),
CVSSv3.1: **9.8**,
EPSS:**01.43**(18.02.2024)| +|[CWE-89: Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')](CWE-707/CWE-89/.)|[CVE-2019-8600](https://www.cvedetails.com/cve/CVE-2019-8600/),
CVSSv3.1: **9.8**,
EPSS:**01.43**(18.02.2024)| |[CWE-117: Improper Output Neutralization for Logs](CWE-707/CWE-117/.)|| |[CWE-180: Incorrect behavior order: Validate before Canonicalize](CWE-707/CWE-180/.)|| ||| @@ -82,9 +84,7 @@ It is **not production code** and requires code-style or python best practices t |[CWE-1109: Use of Same Variable for Multiple Purposes](CWE-710/CWE-1109/.)|| ||| - - -# Biblography +## Biblography |Ref|Detail| |-----|-----| @@ -94,7 +94,7 @@ It is **not production code** and requires code-style or python best practices t |[OWASP 2022]|[OWASP Top 10 Report 2022](https://owasp.org/www-project-top-ten/)| |[MITRE 2023]|[CWE Top 25 2022](https://cwe.mitre.org/top25/archive/2022/2022_cwe_top25.html)| +## License -# License * [CC-BY 4.0](LICENSE/CC-BY-4.0.txt) for documentation * [MIT](LICENSE/MIT.txt) for code snippets