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. Upgrade to Tornado version 6.50 to receive a patch. As a workaround, risk can be mitigated by blocking `Content-Type: multipart/form-data` in a proxy.
CVSS Details
- CVSS 3.1 Base Score: 7.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alma_linux | — | Upgrade python3-tornadoUpgrade pcs-snmpUpgrade pcs | May 27, 2025 | May 15, 2025 |
| Amazon Linux Ami 2 | — | Upgrade python3-tornado-docUpgrade python3-tornadoUpgrade python3-tornado-debuginfoUpgrade python-tornado-debuginfoUpgrade python-tornado-docUpgrade python-tornado | Jun 13, 2025 | May 15, 2025 |
| Amazon_linux_2023 | — | Upgrade python-tornado-docUpgrade python3-tornadoUpgrade python3-tornado-debuginfoUpgrade python-tornado-debugsource | Jun 11, 2025 | May 15, 2025 |
| Debian | — | Upgrade python-tornado | May 20, 2025 | May 15, 2025 |
| Oracle_linux | — | Upgrade python-tornado-docUpgrade pcs-snmpUpgrade python-tornadoUpgrade pcsUpgrade python3-tornado | May 27, 2025 | May 15, 2025 |
| Redhat_linux | — | Upgrade pcs-snmpUpgrade python3-tornadoUpgrade python-tornado-debuginfoUpgrade python-tornado-docUpgrade python-tornadoUpgrade python-tornado-debugsourceUpgrade python3-tornado-debuginfoUpgrade pcsNo solution exists | May 27, 2025 | May 15, 2025 |
| Rocky_linux | — | Upgrade python3-tornadoUpgrade pcsUpgrade python3-tornado-debuginfoUpgrade pcs-snmpUpgrade python-tornado-debugsource | Jul 31, 2025 | Jul 29, 2025 |
| Suse | — | Upgrade salt-minionUpgrade salt-transactional-updateUpgrade python313-tornado6Upgrade salt-bash-completionUpgrade salt-cloudUpgrade salt-docUpgrade salt-zsh-completionUpgrade saltUpgrade python311-tornado6Upgrade salt-sshUpgrade salt-masterUpgrade salt-fish-completionUpgrade salt-proxyUpgrade salt-standalone-formulas-configurationUpgrade python3-tornadoUpgrade salt-syndicUpgrade salt-apiUpgrade python3-saltUpgrade python3-salt-testsuite | Dec 5, 2025 | Jun 1, 2025 |
| Ubuntu | — | Upgrade python3-tornadoUpgrade python3-tornado (Ubuntu Pro) | Jun 4, 2025 | May 15, 2025 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Aug 20, 2025 | May 15, 2025 |
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