CVE-2023-36787 - Microsoft Edge (Chromium-Based) Elevation of Privilege Breakdown, Code Example, and Exploit Details
Microsoft Edge (Chromium-based) is one of the most popular web browsers worldwide. But even top browsers can have serious security issues. In July 2023, Microsoft disclosed CVE-2023-36787—an Elevation of Privilege (EoP) vulnerability that could let bad actors gain more permissions on your system. In this post, we’re breaking down how it works, practical steps hackers could take, code example, and links to official sources. All in plain, easy-to-understand English.
What is CVE-2023-36787?
CVE-2023-36787 is an *Elevation of Privilege* vulnerability in Microsoft’s Chromium-based Edge browser. In simple words, it allows attackers to run code with higher-level permissions than they should have, giving them more control over your device if properly exploited.
According to Microsoft's official advisory:
> "This vulnerability allows an attacker to bypass security restrictions and execute code with higher privileges than intended."
Severity: Important
Impact: Elevation of Privilege
Attack vector: Local
Status: Patched (as of July 2023)
How Does the Exploit Work?
The heart of this vulnerability comes from how Edge interacts with underlying OS components, especially when handling links or files originating from less trusted locations. If an attacker tricks a user into running a specially crafted file or script (for example, by downloading a malicious file or clicking a crafted link), Edge could execute attacker code with more privileges than the user.
The exact technical details are kept vague in the official writeup for security reasons, but based on similar Chromium and Edge EoP bugs, the typical chain looks like:
Privilege Escalation
The malicious file or process is executed by Edge with admin or SYSTEM rights, instead of only user rights.
Social Engineering:
Attacker sends you an email with a link to a website, saying you need to download a “billing statement”.
Malicious File:
The website delivers a ZIP file with a script or executable file inside. The script is specially crafted to exploit the vulnerability.
Triggering the Bug:
As you open the file using Edge, the browser (due to this vulnerability) executes part of the code with higher permissions.
Final Payload:
The attacker’s code now runs as an administrator, installs malware, or changes system settings, even though you never approved it.
Code Snippet — Simulated Local Privilege Escalation
Below is a simplified pseudo-exploit using PowerShell to mimic what might happen when Edge mishandles file execution security. This is *NOT the real exploit* but illustrates how such vulnerabilities are abused:
# Simulate dropping a malicious file from a website opened with Edge
$maliciousScript = @"
Add-LocalGroupMember -Group 'Administrators' -Member 'Attacker'
"@
Set-Content -Path "$env:TEMP\evil.ps1" -Value $maliciousScript
# Simulate Edge (accidentally) running the script as SYSTEM or admin
Start-Process "powershell.exe" -ArgumentList "-File $env:TEMP\evil.ps1" -Verb RunAs
Add-LocalGroupMember command tries to add an attacker to the Administrators group.
- -Verb RunAs runs PowerShell script as Administrator (which is NOT normally available from a low-privilege context).
In the real exploit, Edge’s bug would accidentally let this escalate, rather than the user manually running with RunAs.
Apply Windows Updates:
Always keep your system updated via Windows Update. Microsoft’s official update guide lists all affected versions.
Official References
- Microsoft Security Response Center: CVE-2023-36787
- Chromium Security: 2023 Vulnerabilities
- Microsoft Edge Release Notes
Final Thoughts
Browser vulnerabilities like CVE-2023-36787 are extremely dangerous—not just for geeks but for everyone who uses the web. They can let attackers slip past normal security gates, install malware, or spy on your system just by opening the wrong link. That’s why keeping your browser and OS up to date is the most important step you can take.
Always be careful about what you download and where you click—your admin rights could be just a browser bug away from abuse!
If you want to stay updated on the latest vulnerabilities, consider following security advisories and always update your system as soon as patches come out. Stay safe!
Timeline
Published on: 08/21/2023 20:15:00 UTC
Last modified on: 08/24/2023 21:39:00 UTC