Cross-site scripting via unescaped Host header
Published Oct 26, 2022 · Updated Nov 3, 2025
Cross-site scripting in Twisted before 22.10.0rc1 allows attackers to inject HTML and script through a crafted Host header. NameVirtualHost returns a NoResource page for an unmatched host and inserts the request Host value into the 404 body without HTML escaping. Exploitation requires a privileged position that permits Host-header modification and user interaction, allowing attacker-supplied script to run in the response viewer's browser.
Summary
What happened
Cross-site scripting in Twisted before 22.10.0rc1 allows attackers to inject HTML and script through a crafted Host header. NameVirtualHost returns a NoResource page for an unmatched host and inserts the request Host value into the 404 body without HTML escaping. Exploitation requires a privileged position that permits Host-header modification and user interaction, allowing attacker-supplied script to run in the response viewer's browser.
The record
- CVE
- CVE-2022-39348
- Published
- Oct 26, 2022
- Updated
- Nov 3, 2025
- Vendor
- Twisted
- Product
- Twisted
- Classifications
- CWE-79, CWE-80, T1203
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Oct 26, 2022CVE publishedPublication date reported by the CVE source.
- Nov 3, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 0.9.4, < 22.10.0rc1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- NameVirtualHost crafted Host-header demonstrationproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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