CVE-2024-12254

Description

Starting in Python 3.12.0, the asyncio._SelectorSocketTransport.writelines() method would not "pause" writing and signal to the Protocol to drain the buffer to the wire once the write buffer reached the "high-water mark". Because of this, Protocols would not periodically drain the write buffer potentially leading to memory exhaustion. This vulnerability likely impacts a small number of users, you must be using Python 3.12.0 or later, on macOS or Linux, using the asyncio module with protocols, and using .writelines() method which had new zero-copy-on-write behavior in Python 3.12.0 and later. If not all of these factors are true then your usage of Python is unaffected.

Reserved 2024-12-05 | Published 2024-12-06 | Updated 2025-01-06 | Assigner PSF

Problem types

CWE-400 Uncontrolled Resource Consumption

CWE-770 Allocation of Resources Without Limits or Throttling

Product status

Default status
unaffected

3.12.0 before 3.14.0a2
affected

Credits

J. Nick Koston reporter

Seth Larson coordinator

References

github.com/python/cpython/issues/127655 issue-tracking

github.com/python/cpython/pull/127656 patch

mail.python.org/.../thread/H4O3UBAOAQQXGT4RE3E4XQYR5XLROORB/ vendor-advisory

github.com/...ommit/71e8429ac8e2adc10084ab5ec29a62f4b6671a82 patch

github.com/...ommit/9aa0deb2eef2655a1029ba228527b152353135b5 patch

cve.org (CVE-2024-12254)

nvd.nist.gov (CVE-2024-12254)

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