CVE-2025-67725highCWE-400

CVE-2025-67725: falha de alta gravidade em tornadoweb tornado

Tornado is Vulnerable to Quadratic DoS via Repeated Header Coalescing

Publicada em · Atualizada em

Aviso por e-mail quando ela entrar no KEV, ganhar PoC pública ou subir de nota.

21Vexday Risk Score

Sem sinal de exploração. Nenhum artefato público de exploração conhecido até agora.

ssvc Trackcvss 7.5epss 0.6%
Tornado is a Python web framework and asynchronous networking library. In versions 6.5.2 and below, a single maliciously crafted HTTP request can block the server's event loop for an extended period, caused by the HTTPHeaders.add method. The function accumulates values using string concatenation when the same header name is repeated, causing a Denial of Service (DoS). Due to Python string immutability, each concatenation copies the entire string, resulting in O(n²) time complexity. The severity can vary from high if max_header_size has been increased from its default, to low if it has its default value of 64KB. This issue is fixed in version 6.5.3.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Produtos afetados
tornadoweb · tornado