CVE-2025-47287Allocation of Resources Without Limits or Throttling in Tornado

Severity
7.5HIGHNVD
EPSS
1.2%
top 21.37%
CISA KEV
Not in KEV
Exploit
No known exploits
Timeline
PublishedMay 15
Latest updateJun 2

Description

Tornado is a Python web framework and asynchronous networking library. When Tornado's ``multipart/form-data`` parser encounters certain errors, it logs a warning but continues trying to parse the remainder of the data. This allows remote attackers to generate an extremely high volume of logs, constituting a DoS attack. This DoS is compounded by the fact that the logging subsystem is synchronous. All versions of Tornado prior to 6.5.0 are affected. The vulnerable parser is enabled by default. Upg

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitability: 3.9 | Impact: 3.6

Affected Packages3 packages

debiandebian/python-tornado< python-tornado 6.2.0-3+deb12u2 (bookworm)
NVDtornadoweb/tornado< 6.5.0
PyPItornadoweb/tornado< 6.5

Also affects: Debian Linux 11.0

Patches

🔴Vulnerability Details

4
OSV
python-tornado vulnerability2025-06-02
GHSA
Tornado vulnerable to excessive logging caused by malformed multipart form data2025-05-16
OSV
Tornado vulnerable to excessive logging caused by malformed multipart form data2025-05-16
OSV
CVE-2025-47287: Tornado is a Python web framework and asynchronous networking library2025-05-15

📋Vendor Advisories

3
Ubuntu
Tornado vulnerability2025-06-02
Red Hat
tornado: Tornado Multipart Form-Data Denial of Service2025-05-15
Debian
CVE-2025-47287: python-tornado - Tornado is a Python web framework and asynchronous networking library. When Torn...2025
CVE-2025-47287 — Tornadoweb Tornado vulnerability | cvebase