Authentication bypass via multiple XML roots
Published Oct 13, 2022 · Updated Apr 23, 2025
Signature verification flaw in Node SAML before 4.0.0-beta.5 allows remote attackers to bypass SAML authentication with crafted XML. The response validator accepted a valid signature on the document element without ensuring that the parsed XML contained only one root element, allowing attacker-controlled assertion content in a second root. Exploitation requires an arbitrary IdP-signed XML element; it is fully unauthenticated when the IdP can be induced to generate one.
Summary
What happened
Signature verification flaw in Node SAML before 4.0.0-beta.5 allows remote attackers to bypass SAML authentication with crafted XML. The response validator accepted a valid signature on the document element without ensuring that the parsed XML contained only one root element, allowing attacker-controlled assertion content in a second root. Exploitation requires an arbitrary IdP-signed XML element; it is fully unauthenticated when the IdP can be induced to generate one.
The record
- CVE
- CVE-2022-39300
- Published
- Oct 13, 2022
- Updated
- Apr 23, 2025
- Vendor
- node-saml
- Product
- Node SAML
- Classifications
- CWE-347, T1606.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 13, 2022CVE publishedPublication date reported by the CVE source.
- Apr 23, 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=< 4.0.0-beta.5
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
- Multiple-root signed SAML response regression fixtureproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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