CVE-2025-54419
Description
A signature verification flaw was found in the npm @node-saml/node-saml library. This flaw allows an attacker who has access to a validly signed document from the identity provider (IdP) to alter the content of the document, modify the details within the document, and have the modifications be accepted.
Statement
This is a Important impact authn-bypass, not a Moderate bug, because it breaks the core trust boundary of SAML: the service provider (SP) makes authorization decisions based on an assertion it believes is protected by the IdP’s XML signature. In @node-saml/node-saml ≤5.0.1, the library verifies the signature over one part of the response but then parses/uses fields from the original, unsigned document, a classic signature-wrapping/mismatch flaw. An attacker who possesses any validly signed SAML response (e.g., their own login, a captured response, or one from a lower-privileged account) can alter critical elements—such as the Subject/NameID (e.g., drop a character to map to a different user), group/role attributes, AuthnContext, or Conditions—without invalidating the signature, and the SP will accept the modified values. That enables account takeover, privilege escalation, MFA/step-up bypass (via AuthnContext changes), and policy circumvention across every SP relying on this library. The only prerequisite is access to a single signed response; no IdP compromise is required.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.4 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | High | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | High | N/A | N/A |
| Integrity Impact | High | N/A | N/A |
| Availability Impact | None | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Understanding the Weakness (CWE)
Access Control,Integrity,Confidentiality
Technical Impact: Gain Privileges or Assume Identity; Modify Application Data; Execute Unauthorized Code or Commands
An attacker could gain access to sensitive data and possibly execute unauthorized code.
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