Vulnerability 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.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/python/cpython/commit/71e8429ac8e2adc10084ab5ec29a62f4b6671a8
- https://github.com/python/cpython/commit/9aa0deb2eef2655a1029ba228527b152353135b
- https://github.com/python/cpython/commit/e991ac8f2037d78140e417cc9a9486223eb3e78
- https://github.com/python/cpython/issues/127655
- https://github.com/python/cpython/pull/127656
- https://mail.python.org/archives/list/[email protected]/thread/H4O3UB
- http://www.openwall.com/lists/oss-security/2024/12/06/1
- https://security.netapp.com/advisory/ntap-20250404-0010/
FAQ
What is CVE-2024-12254?
CVE-2024-12254 is a vulnerability with a CVSS score of 7.5 (HIGH). 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...
How severe is CVE-2024-12254?
CVE-2024-12254 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2024-12254?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.