CVE-2025-67726

{"id": "CVE-2025-67726", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2025-67726", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2025-12-18T18:47:53.473225Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "tornadoweb", "product": "tornado", "versions": [{"status": "affected", "version": "< 6.5.3"}]}]}], "published": "2025-12-12T07:15:44.920", "references": [{"url": "https://github.com/tornadoweb/tornado/commit/771472cfdaeebc0d89a9cc46e249f8891a6b29cd", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/tornadoweb/tornado/releases/tag/v6.5.3", "tags": ["Release Notes"], "source": "security-advisories@github.com"}, {"url": "https://github.com/tornadoweb/tornado/security/advisories/GHSA-jhmp-mqwm-3gq8", "tags": ["Vendor Advisory"], "source": "security-advisories@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-400"}, {"lang": "en", "value": "CWE-834"}]}], "descriptions": [{"lang": "en", "value": "Tornado is a Python web framework and asynchronous networking library. Versions 6.5.2 and below use an inefficient algorithm when parsing parameters for HTTP header values, potentially causing a DoS. The _parseparam function in httputil.py is used to parse specific HTTP header values, such as those in multipart/form-data and repeatedly calls string.count() within a nested loop while processing quoted semicolons. If an attacker sends a request with a large number of maliciously crafted parameters in a Content-Disposition header, the server's CPU usage increases quadratically (O(n\u00b2)) during parsing. Due to Tornado's single event loop architecture, a single malicious request can cause the entire server to become unresponsive for an extended period. This issue is fixed in version 6.5.3."}, {"lang": "es", "value": "Tornado es un framework web de Python y una biblioteca de red as\u00edncrona. Las versiones 6.5.2 e inferiores utilizan un algoritmo ineficiente al analizar par\u00e1metros para valores de encabezado HTTP, lo que podr\u00eda causar un DoS. La funci\u00f3n _parseparam en httputil.py se utiliza para analizar valores espec\u00edficos de encabezado HTTP, como los de multipart/form-data, y llama repetidamente a string.count() dentro de un bucle anidado mientras procesa puntos y coma 'entre comillas'. Si un atacante env\u00eda una solicitud con un gran n\u00famero de par\u00e1metros creados maliciosamente en un encabezado Content-Disposition, el uso de CPU del servidor aumenta cuadr\u00e1ticamente (O(n\u00b2)) durante el an\u00e1lisis. Debido a la arquitectura de bucle de eventos \u00fanico de Tornado, una \u00fanica solicitud maliciosa puede hacer que todo el servidor deje de responder durante un per\u00edodo prolongado. Este problema se soluciona en la versi\u00f3n 6.5.3."}], "lastModified": "2026-10-07T20:10:01.970", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:tornadoweb:tornado:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "64279E50-159B-4CAB-9BD0-E2B764C3C40C", "versionEndExcluding": "6.5.3"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}