Technology is an integral part of our lives, but unfortunately, cyber threats are constantly on the rise. Recently, a new vulnerability has been discovered, known as CVE-2021-36934, which poses a significant risk to computer systems.
This vulnerability can potentially allow attackers to access sensitive data on Windows systems, compromising the privacy and security of individuals and organizations. Let’s look at the details of this vulnerability, its impact, and mitigation strategies for system protection.
What is CVE-2021-36934?
CVE-2021-36934 is a security vulnerability that was discovered in the Windows operating system. The vulnerability, also known as “Windows Elevation of Privilege Vulnerability,” exists to give attackers access and read sensitive multiple system files on affected systems.
It is a vulnerability in the Microsoft Windows operating system that allows non-administrative users to access the sensitive data stored in the Security Account Manager (SAM) file, which is used for keeping passwords and other security-related information. The vulnerability was discovered in July 2021 by security researchers and was publicly disclosed in August 2021.
CVE-2021-36934 is a serious vulnerability that highlights the importance of keeping systems up to date with the latest security patches and updates. Failure to do so can leave systems exposed to malware attacks, compromising the security and privacy of sensitive data stored on these systems.
Analysis of the CVE-2021-36934 Vulnerability
The vulnerability allows non-administrative users to read the contents of the Security Accounts Manager (SAM) file, which contains encrypted passwords and other sensitive information about user accounts on the system.
This can allow attackers to access user accounts and compromise the system’s security. The vulnerability affects all versions of Windows 10 and some earlier versions of Windows as well.
The vulnerability was caused by the incorrect permissions set on the SAM file, which allowed non-administrative users to access the file. Microsoft has since released security patches and updates to address the vulnerability, and users are advised to install these updates as soon as possible to mitigate the risk of exploitation.
Exploitation of CVE-2021-36934
The exploitation of CVE-2021-36934 involves taking advantage of the Windows Volume Shadow Copy Service (VSS), which is used to create snapshots of a system’s files and folders.
Attackers can use this service to create a copy of the SAM database, which is stored in an unprotected location on the system. The attacker can then access the copy of the SAM database and extract the password hashes for all user accounts on the system.
Once the attacker has access to the password hashes, they can use various methods to crack the passwords and gain access to the system. This can compromise sensitive data, such as financial or personal data, severely affecting individuals or organizations.
If this vulnerability is successfully exploited, it may result in a local attacker obtaining complete control over the system and executing arbitrary code with system privileges. Once elevated privileges are acquired, the attacker can install unauthorized programs and gain access to, modify, or delete unauthorized data on the system.
Impact of CVE-2021-36934
The impact of CVE-2021-36934 is far-reaching, as it affects all supported versions of Microsoft Windows, including Windows 10 and Windows Server. If exploited, the vulnerability can allow attackers to bypass security controls, gain unauthorized access to sensitive data, and compromise the integrity of the affected system.
The risk of this vulnerability is exceptionally high for organizations that use Windows systems for critical operations or handle sensitive data. The potential exposure of user account passwords can lead to data breaches, identity theft, and other malicious activities.
Furthermore, the impact of CVE-2021-36934 is not limited to the immediate consequences of an attack. The exposure of user account passwords can have long-term consequences, as attackers can continue to use stolen credentials to gain unauthorized access to systems and networks long after the initial breach.
Mitigation Strategies of CVE-2021-36934
CVE-2021-36934 is a vulnerability that affects the readability of Microsoft’s Security Account Manager (SAM) files, which contain sensitive information such as user passwords. Mitigating this vulnerability is critical to prevent unauthorized access to this sensitive data.
1. Restricting Access to %windir%system32config:
The first step is to restrict access to the contents of %windir%system32config, where the SAM database is stored. To do this, you can follow these steps:
- Open the Windows Command Prompt as an administrator.
- Type “icacls %windir%system32config*.* /inheritance:e” and press Enter. This command will disable the inheritance of permissions for all system files in the config folder, so they won’t be accessible to users who are not explicitly authorized to access them.
- Type “icacls %windir%system32configsam /grant:Administrators:(RX)” and press Enter. This command will grant the administrator’s group read and execute permissions to the SAM file.
- Type “icacls %windir%system32config*.* /remove Users” and press Enter. This command will remove all permissions for the Users group, so they won’t be able to access any system files in the config folder.
2. Delete Volume Shadow Copy Service (VSS) Shadow Copies
The second mitigation approach is to delete the Volume Shadow Copy Service (VSS) shadow copies. The VSS service takes periodic snapshots of the system, including the SAM database, to allow system recovery in case of an issue. However, these shadow copies can also access the SAM database without permission.
To delete VSS shadow copies or any System Restore points, follow these steps:
- Open the Windows Command Prompt as an administrator.
- Type “vssadmin list shadows” and press Enter. This command will display a list of all VSS shadow copies on the system.
- Type “vssadmin delete shadows /for=c:” and press Enter. This command will delete all VSS shadow copies on the C: drive. Replace “c:” with the appropriate drive letter for other drives.
- If you want, you can create a new System Restore point.
Other tips you can be taken to mitigate CVE-2021-36934 include the following:
- Apply the security updates released by Microsoft: Microsoft has released security updates to address CVE-2021-36934. Applying these updates as soon as possible is highly recommended to prevent potential vulnerability exploits.
- Implement the principle of least privilege: The principle of least privilege involves giving users only the minimum access necessary to perform their tasks. This can help to minimize the risk of unauthorized access to sensitive information, including SAM files.
- Enable security auditing: Enabling security auditing on SAM files can help to detect any unauthorized access attempts or changes made to these files. This can also help to identify insider threats to cyber security, check on potential security breaches and take appropriate actions.
- Implement multi-factor authentication: Implementing multi-factor authentication for users accessing SAM files can add a layer of security and prevent unauthorized access.
Conclusion on CVE-2021-36934
CVE-2021-36934 is a severe vulnerability that could have devastating consequences if left unaddressed. As technology advances and our reliance on digital systems increases, it is more important than ever to stay vigilant and proactive in identifying and addressing vulnerabilities.
System administrators and users should ensure system protection by implementing patches and workarounds as needed. By working together and staying informed, we can help to mitigate the risks posed by vulnerabilities such as CVE-2021-36934 and keep our digital systems secure.
Frequently Asked Questions (FAQs) on CVE-2021-36934
1. Does the security update fully mitigate the CVE-2021-36934 vulnerability?
The security update released by Microsoft aims to address the vulnerability, restore data, and provide protection against it. However, it is essential to note that no security measure can guarantee 100% protection against all potential threats. Therefore, while the security update is a crucial step towards mitigating the CVE-2021-36934 vulnerability, it is essential also to follow recommended security practices and protocols.
2. What versions are affected by CVE-2021-36934?
The CVE-2021-36934 vulnerability affects all currently supported versions of Windows, including Windows 10 and Windows Server. The vulnerability arises from how the Microsoft SAM file handles user account data. It is recommended that users update their systems to the latest version and apply the security patches released by Microsoft to mitigate this vulnerability.
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