Resource exhaustion in Python Software Foundation Cpython

CVE-2024-12254

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.

Vulnerability class: DoS (Denial of Service)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.019 (78.5th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 78th percentile — 78.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2024-12254: held from 0.019 to 0.019.

EPSS over last 30 days · oldest: 0.019 · newest: 0.019 · change: -0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2024-12254?
CVE-2024-12254 is a high-severity vulnerability in Python Software Foundation Cpython, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2024-12-06.
How severe is CVE-2024-12254?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2024-12254 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.