Bug 2421719 (CVE-2025-67724)

Summary: CVE-2025-67724 tornado: Tornado Header Injection and XSS via reason argument
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: bbrownin, caswilli, eglynn, jjoyce, jkoehler, jschluet, kaycoth, lhh, lphiri, mburns, mgarciac
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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An unescaped input flaw has been discovered in the Tornado networking library. In Tornado, the supplied reason phrase is used unescaped in HTTP headers (where it could be used for header injection) or in HTML in the default error page (where it could be used for XSS) and can be exploited by passing untrusted or malicious data into the reason argument. Used by both RequestHandler.set_status and tornado.web.HTTPError, the argument is designed to allow applications to pass custom "reason" phrases (the "Not Found" in HTTP/1.1 404 Not Found) to the HTTP status line (mainly for non-standard status codes).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2421926, 2421925, 2421927, 2421928    
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Description OSIDB Bzimport 2025-12-12 10:18:58 UTC
Tornado is a Python web framework and asynchronous networking library. In versions 6.5.2 and below, the supplied reason phrase is used unescaped in HTTP headers (where it could be used for header injection) or in HTML in the default error page (where it could be used for XSS) and can be exploited by passing untrusted or malicious data into the reason argument. Used by both RequestHandler.set_status and tornado.web.HTTPError, the argument is designed to allow applications to pass custom "reason" phrases (the "Not Found" in HTTP/1.1 404 Not Found) to the HTTP status line (mainly for non-standard status codes). This issue is fixed in version 6.5.3.