External risk intelligence

OpenSIAC Cl@ve Authentication Impersonation Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.3)

CVE-2025-41064

The vulnerability affects an authentication method (Cl@ve) within an identity service or integration platform (OpenSIAC). Authentication portals and identity gateways are designed to be public-facing to facilitate user access, making the vulnerable surface inherently internet-exposed in typical deployments.

Authentication Bypass

Halo Surface Signal: 5 out of 5 — more likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

This vulnerability in OpenSIAC could allow an unauthorized individual to impersonate users authenticated via the Cl@ve method. The primary concern is to confirm if your organization utilizes this specific authentication mechanism with OpenSIAC to assess relevance.

  • Attackers can impersonate users using Cl@ve.
  • Authentication flaws have broad implications.
  • Confirm usage of Cl@ve with OpenSIAC.

Attack Path

How an attacker could exploit the issue

An attacker could impersonate users by exploiting a flaw in how OpenSIAC handles authentication through the Cl@ve system. This could allow them to gain unauthorized access to accounts and sensitive information.

  • No authentication required.
  • Cl@ve authentication method.
  • Impersonate users.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability in OpenSIAC could allow an attacker to impersonate users who authenticate using Cl@ve. When supported by the advisory, this could affect the integrity of user sessions and system access by enabling unauthorized actions on behalf of legitimate users.

  • User identities and access could be affected.
  • Attackers could impersonate users via authentication.
  • Unauthorized actions may occur on the system.

Operational Fix

Recommended remediation, mitigation, and detection steps

The criticality of this authentication vulnerability in OpenSIAC, which could allow for impersonation via Cl@ve, necessitates a focused response. Responsibility likely falls to teams managing identity and access management (IAM) or application platforms, alongside network and security operations for exposure assessment. The immediate first step is to determine the presence and reachability of OpenSIAC instances utilizing Cl@ve, confirm their business criticality, and identify the system owner to initiate a risk-based remediation plan.

  • Identify the accountable system owner.
  • Verify Cl@ve authentication reachability.
  • Plan remediation based on identified risk.

Supplementary metadata

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

Frequently asked questions

What is OpenSIAC?

OpenSIAC is an identity service platform used to manage user authentication and integration processes. It acts as a bridge for various authentication methods, allowing systems to verify user identities. In this context, it specifically facilitates connections to the Cl@ve identity system, which is a common platform for accessing public administration services.

What does CWE-287 mean for CVE-2025-41064?

CWE-287 refers to Improper Authentication. This means the software fails to correctly verify the identity of a user, allowing them to bypass security checks. For CVE-2025-41064, this vulnerability allows an unauthorized person to successfully impersonate a legitimate user who is trying to sign in using the Cl@ve method, effectively tricking the system into granting them access.

How does an attacker trigger this authentication flaw?

The vulnerability does not require the attacker to have prior credentials or user interaction. By targeting the specific way OpenSIAC processes Cl@ve authentication requests, an attacker can manipulate the handshake or validation flow. It is important to note that this flaw specifically impacts the integration with Cl@ve; systems not using this specific method are not triggered by this authentication path.

Is my instance affected by this vulnerability?

According to Halo Surface Signal, this vulnerability is considered highly relevant because OpenSIAC and its authentication portals are typically designed to be internet-facing to support user access. If your organization uses OpenSIAC to handle Cl@ve-based logins, your instance is likely exposed. You should prioritize checking if your deployment is reachable from the public internet.

What steps should I take if I use OpenSIAC?

First, confirm if your organization has instances of OpenSIAC that integrate with the Cl@ve system. Once identified, determine who owns and manages these systems. Coordinate with your identity and access management team to verify the reachability of these services and assess their business criticality to develop a prioritized remediation plan.

References