Skip to main content

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVE-2025-67724

Medium
6.1/10

Summary

Tornado is a Python web framework and asynchronous networking library. In versions through 6.5.2 , 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 Cross-Site Scripting (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.

  • LOW
  • NETWORK
  • LOW
  • CHANGED
  • REQUIRED
  • NONE
  • LOW
  • NONE

CWE-79 - Cross Site Scripting

Cross-Site Scripting, commonly referred to as XSS, is the most dominant class of vulnerabilities. It allows an attacker to inject malicious code into a pregnable web application and victimize its users. The exploitation of such a weakness can cause severe issues such as account takeover, and sensitive data exfiltration. Because of the prevalence of XSS vulnerabilities and their high rate of exploitation, it has remained in the OWASP top 10 vulnerabilities for years.

References

Advisory Timeline

  • Published