In June 2022, Microsoft revealed a concerning vulnerability in SharePoint Server—CVE-2022-30157. This flaw opened the door for remote attackers to potentially run code on a target’s SharePoint server. If you manage or use SharePoint in any form, keep reading to get the full story, how it works, and—most importantly—how to protect yourself. This is not the same flaw as CVE-2022-30158, but has its own unique risks and details.

What is CVE-2022-30157?

CVE-2022-30157 is a Remote Code Execution (RCE) vulnerability found in Microsoft SharePoint Server. In simple terms: a remote attacker, with enough access, could exploit a bug in SharePoint’s processing to run their own commands or code as if they were your SharePoint server.

Create new accounts with full user rights

Microsoft classified the flaw as Important, but the real-world impact depends on your organization's setup and use of SharePoint.

SharePoint Server Subscription Edition

For the full, up-to-date list, check the Microsoft Security Update Guide for CVE-2022-30157.

What’s the Technical Cause?

Microsoft’s advisory doesn’t spill every technical detail, but based on patch code and community research, here’s what’s known:

The vulnerability lies in how SharePoint validates user-supplied input.

- An authenticated user (typically with least "Site Member" permissions) can craft a special web request to SharePoint that bypasses validation and, by manipulating some internals, eventually gets SharePoint’s process to run attacker-controlled code.

Authentication Required: The attacker must log in to SharePoint to exploit this vulnerability.

Login: The attacker signs in as a regular (non-admin) user.

2. Malicious Request: Sends a specially-crafted HTTP POST to a vulnerable SharePoint page or endpoint.

Bypass Validation: The submitted data exploits poor input checks, letting it sneak through.

4. Code Execution: SharePoint parses the request, and at some point processes & executes the attacker’s payload as server code.

Example Exploit (Illustration)

Below is a sample PowerShell code snippet that simulates the core idea—DO NOT RUN IT AGAINST LIVE SYSTEMS! It is for educational awareness, not attack.

Let’s say there’s a vulnerable endpoint like /sites/target/_layouts/15/somepage.aspx. The attacker crafts a payload to deploy a web shell (a file that lets them run more commands).

# Set up the variables
$SPUrl = "https://sharepoint.example.com/sites/target/_layouts/15/somepage.aspx";
$Creds = Get-Credential  # Attacker needs working login

# Create malicious payload (for example, a simple ASPX web shell)
$Payload = '<%@ Page Language="C#" %><% Response.Write("PWNED"); %>'

# Set up web request
$WebRequest = Invoke-WebRequest -Uri $SPUrl -Method POST `
  -Credential $Creds `
  -Body @{ file = $Payload; filename = "shell.aspx" }

# Check for success
if ($WebRequest.StatusCode -eq 200) {
    Write-Host "[+] Payload sent! Check for web shell."
} else {
    Write-Host "[-] Failed. Server returned status $($WebRequest.StatusCode)."
}


This example is not a working exploit against up-to-date SharePoint, but it captures the kind of attack made possible: uploading a payload and getting it processed/executed on the back end.

Did This Happen In The Wild?

As of the initial disclosure (June 2022), Microsoft had no confirmed reports of exploitation in the wild. However, given the ubiquity of SharePoint, public exploit write-ups and scanning attempts soon followed.

For example, see CVE-2022-30157 write-ups on GitHub and discussions in exploit forums.

Find your SharePoint version.

- Apply the latest security updates from Microsoft. Download directly from MSRC Security Update Guide.

Additional References

- Microsoft Advisory: CVE-2022-30157
- NVD Entry
- [[PATCH DETAILS] SharePoint Server June 2022 Update](https://techcommunity.microsoft.com/t5/sharepoint-blog/microsoft-sharepoint-server-updates-june-2022/ba-p/350585)

Final Thoughts

CVE-2022-30157 is a reminder: no platform, even Microsoft SharePoint, is immune to exploitation risks, especially from logged-in users. Isolation, regular patching, and minimal permissions are key to defense. If you use SharePoint—even internally—patch now!

Stay secure, stay updated.

*If you found this explanation helpful, consider sharing it with your IT team or others at risk from this critical SharePoint vulnerability.*

Timeline

Published on: 06/15/2022 22:15:00 UTC
Last modified on: 06/26/2022 03:45:00 UTC