CVE-2022-39348Medium· 5.4▾ SunlitTwisted vulnerable to NameVirtualHost Host header injection
▾ Sunlit zone — Low / medium · no exploitation signal
impact 29.7 · likelihood 0.2 · exploitation 0
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Exploit-prediction probability, daily snapshots since Jul 8.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via OSV
Last analysed / modified upstream
1.2%
1.2% → 1.2%
When the host header does not match a configured host, twisted.web.vhost.NameVirtualHost will return a NoResource resource which renders the Host header unescaped into the 404 response allowing HTML and script injection.
Example configuration:
from twisted.web.server import Site
from twisted.web.vhost import NameVirtualHost
from twisted.internet import reactor
resource = NameVirtualHost()
site = Site(resource)
reactor.listenTCP(8080, site)
reactor.run()
Output:
❯ curl -H"Host:<h1>HELLO THERE</h1>" http://localhost:8080/
<html>
<head><title>404 - No Such Resource</title></head>
<body>
<h1>No Such Resource</h1>
<p>host b'<h1>hello there</h1>' not in vhost map</p>
</body>
</html>
This vulnerability was introduced in f49041bb67792506d85aeda9cf6157e92f8048f4 and first appeared in the 0.9.4 release.
twisted >= 0.9.4, < 22.10.0rc1Upgrade to a patched release:
twisted 22.10.0rc1Connected by shared product, vendor, weakness, or advisory.