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 python-tornado-docUpgrade python-tornado-debuginfoUpgrade python-tornadoUpgrade python3-tornado-debuginfoUpgrade python3-tornadoUpgrade python3-tornado-doc | Jun 13, 2025 | May 15, 2025 |
| Amazon_linux_2023 | — | Upgrade python-tornado-docUpgrade python3-tornadoUpgrade python-tornado-debugsourceUpgrade python3-tornado-debuginfo | Jun 11, 2025 | May 15, 2025 |
| Debian | — | Upgrade python-tornado | May 20, 2025 | May 15, 2025 |
| Oracle_linux | — | Upgrade python-tornadoUpgrade python-tornado-docUpgrade pcs-snmpUpgrade pcsUpgrade python3-tornado | May 27, 2025 | May 15, 2025 |
| Redhat_linux | — | Upgrade python3-tornadoUpgrade python-tornado-debuginfoUpgrade python-tornado-docUpgrade pcs-snmpUpgrade python-tornado-debugsourceNo solution existsUpgrade python3-tornado-debuginfoUpgrade python-tornadoUpgrade pcs | May 27, 2025 | May 15, 2025 |
| Rocky_linux | — | Upgrade python3-tornado-debuginfoUpgrade python3-tornadoUpgrade pcsUpgrade python-tornado-debugsourceUpgrade pcs-snmp | Jul 31, 2025 | Jul 29, 2025 |
| Suse | — | Upgrade python3-saltUpgrade python3-tornadoUpgrade salt-apiUpgrade salt-standalone-formulas-configurationUpgrade python3-salt-testsuiteUpgrade salt-syndicUpgrade salt-docUpgrade salt-cloudUpgrade python311-tornado6Upgrade salt-bash-completionUpgrade salt-masterUpgrade python313-tornado6Upgrade salt-minionUpgrade salt-fish-completionUpgrade salt-sshUpgrade salt-proxyUpgrade salt-zsh-completionUpgrade salt-transactional-updateUpgrade salt | Dec 5, 2025 | Jun 1, 2025 |
| Ubuntu | — | Upgrade python3-tornado (Ubuntu Pro)Upgrade python3-tornado | 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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