User impersonation via first-signature-only SAML validation
Published Feb 18, 2025 · Updated Feb 18, 2025
Improper authentication in CIE.AspNetCore.Authentication before 2.1.0 allows remote attackers to impersonate any SPID or CIE user. VerifySignature loads only nodeList[0] into SignedXml, so a signed injected XML element is accepted while the root response and later signatures remain unchecked. No credentials or user interaction are required; an IdP-signed metadata element is sufficient to establish an arbitrary user's session.
Summary
What happened
Improper authentication in CIE.AspNetCore.Authentication before 2.1.0 allows remote attackers to impersonate any SPID or CIE user. VerifySignature loads only nodeList[0] into SignedXml, so a signed injected XML element is accepted while the root response and later signatures remain unchecked. No credentials or user interaction are required; an IdP-signed metadata element is sufficient to establish an arbitrary user's session.
The record
- CVE
- CVE-2025-24895
- Published
- Feb 18, 2025
- Updated
- Feb 18, 2025
- Vendor
- Developers Italia
- Product
- CIE.AspNetCore.Authentication
- Classifications
- CWE-287, T1606.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 18, 2025CVE publishedPublication date reported by the CVE source.
- Feb 18, 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=< 2.1.0
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
- Upstream SAML response bypass proof of conceptproof 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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