Privilege Escalation Unlocked: CVE-2025-53762 in Microsoft Purview (Permissive Input List Flaw)

CVE-2025-53762 is a privilege escalation flaw in Microsoft Purview with a CVSS score of 8.7. One misconfigured input validation routine can give attackers administrative power over an organization's cloud data governance, and a subtle logic error like this one can lead to lateral movement and data compromise across enterprise networks. Purview is one of the most widely adopted data governance platforms, so security teams should deal with this vulnerability immediately.

Technical Information

Vulnerability Mechanism

CVE-2025-53762 is classified under CWE-183: Permissive List of Allowed Inputs (MITRE CWE-183). Some of Microsoft Purview's input validation mechanisms relied on an allow-list that was too broad. Instead of restricting inputs to a minimal, explicitly defined set, the system accepted a wide range of values, including some that an attacker could weaponize.

Exploitation Flow

1. Initial Access: The attacker must possess valid credentials, obtained through phishing, credential stuffing, or an insider threat.
2. Payload Injection: Using the web interface or API, the attacker submits crafted input that mimics allowed patterns but contains embedded privilege escalation payloads.
3. Privilege Escalation: The insufficiently restrictive allow-list fails to block the malicious input, and Purview's privilege assignment logic then processes it. The attacker gains elevated permissions, potentially up to administrative access.

Attack Vectors

• Web Interface: Malicious input submitted through Purview's GUI forms.
• API Endpoints: Crafted requests sent to RESTful APIs used for metadata ingestion, policy configuration, or role management.

Root Cause

The flaw sits in the input validation logic:

# Pseudocode illustration of the flawed logic
allowed_inputs = ["user", "admin", "data_reader", "*"]  # '*' is too permissive
if user_input in allowed_inputs:
    grant_privilege(user_input)

A more secure approach would strictly enumerate allowed roles and reject any input not on the list:

# Secure input validation
strict_allowed_inputs = ["user", "data_reader"]
if user_input in strict_allowed_inputs:
    grant_privilege(user_input)
else:
    reject_input()

In the vulnerable versions, the allow-list either included wildcards or failed to sanitize input for embedded privilege escalation payloads, so attackers could bypass the intended access controls.

Affected Components

• Metadata ingestion pipelines
• Access policy managers
• Integration endpoints (e.g., Azure Synapse Analytics connectors)

Patch Information

Microsoft has released a security update that fixes this vulnerability. The patch enforces stricter input validation: it removes the overly permissive allow-list and accepts only explicitly authorized inputs. To apply the fix:

1. Open the Microsoft Security Update Guide entry: MSRC CVE-2025-53762
2. Review the update details, including affected systems and prerequisites.
3. Select and download the appropriate update package.
4. Install it by following the installation instructions.
5. Confirm the update is applied through system update history or verification tools.

Apply this update promptly to prevent privilege escalation attacks in Microsoft Purview environments.

Affected Systems and Versions

• Product: Microsoft Purview
• Affected versions: As of July 18, 2025, public advisories have not disclosed specific version numbers. Treat all currently supported Microsoft Purview deployments as potentially vulnerable until patched.
• Vulnerable configurations: Any configuration where user-supplied input is accepted for role assignment, metadata ingestion, or policy management.

Vendor Security History

Microsoft has long had a reputation for responding quickly to vulnerabilities, especially in its cloud and enterprise products. The May and June 2025 Patch Tuesday cycles fixed dozens of vulnerabilities, including privilege escalation and input validation issues in other Azure services. Microsoft Purview is a relatively new part of the Azure ecosystem, but it is tied into critical data and compliance workflows, which makes any privilege escalation flaw in it especially serious. Microsoft has historically released patches for critical vulnerabilities within days of public disclosure, which reflects a mature security process.

References

• NVD Entry for CVE-2025-53762
• Microsoft Security Update Guide: CVE-2025-53762
• Official CVE Record
• Red Hot Cyber CVE Coverage
• MITRE CWE-183: Permissive List of Allowed Inputs

Source: This report was created using AI

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