Description
Sandboxie is a sandbox-based isolation software for 32-bit and 64-bit Windows NT-based operating systems. An authenticated user (**UserA**) with no privileges is authorized to read all files created in sandbox belonging to other users in the sandbox folders `C:\Sandbox\UserB\xxx`. An authenticated attacker who can use `explorer.exe` or `cmd.exe` outside any sandbox can read other users' files in `C:\Sandbox\xxx`. By default in Windows 7+, the `C:\Users\UserA` folder is not readable by **UserB**. All files edited or created during the sandbox processing are affected by the vulnerability. All files in C:\Users are safe. If `UserB` runs a cmd in a sandbox, he will be able to access `C:\Sandox\UserA`. In addition, if **UserB** create a folder `C:\Sandbox\UserA` with malicious ACLs, when **UserA** will user the sandbox, Sandboxie doesn't reset ACLs ! This issue has not yet been fixed. Users are advised to limit access to their systems using Sandboxie.
EPSS Score:
0%
Comprehensive Technical Analysis of EUVD-2024-43788
1. Vulnerability Assessment and Severity Evaluation
Vulnerability Description:
The vulnerability in Sandboxie, a sandbox-based isolation software, allows an authenticated user with no privileges to read files created in the sandbox by other users. This unauthorized access can occur through explorer.exe or cmd.exe outside the sandbox. Additionally, the vulnerability allows a user to create folders with malicious Access Control Lists (ACLs) that are not reset by Sandboxie, potentially leading to further unauthorized access.
Severity Evaluation:
The CVSS (Common Vulnerability Scoring System) base score of 9.2 indicates a critical vulnerability. The scoring vector CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L breaks down as follows:
- Attack Vector (AV): Local (L)
- Attack Complexity (AC): Low (L)
- Privileges Required (PR): None (N)
- User Interaction (UI): None (N)
- Scope (S): Changed (C)
- Confidentiality Impact (C): High (H)
- Integrity Impact (I): High (H)
- Availability Impact (A): Low (L)
This high severity is due to the potential for significant confidentiality and integrity impacts, even though the attack vector is local and requires no special privileges or user interaction.
2. Potential Attack Vectors and Exploitation Methods
Attack Vectors:
- Unauthorized File Access: An authenticated attacker can use
explorer.exeorcmd.exeto read files in the sandbox folders of other users. - Malicious ACL Creation: An attacker can create folders with malicious ACLs in the sandbox directory, which are not reset by Sandboxie, allowing persistent unauthorized access.
Exploitation Methods:
- File Reading: The attacker can navigate to
C:\Sandbox\UserB\xxxand read files created by other users. - ACL Manipulation: The attacker can create a folder
C:\Sandbox\UserAwith malicious ACLs, which will not be reset by Sandboxie, leading to unauthorized access when the legitimate user accesses the sandbox.
3. Affected Systems and Software Versions
Affected Systems:
- Windows 7 and later versions.
Affected Software Versions:
- Sandboxie versions prior to v1.14.6 / 5.69.6.
4. Recommended Mitigation Strategies
Immediate Mitigation:
- Access Control: Limit access to systems using Sandboxie to trusted users only.
- Monitoring: Implement monitoring to detect unauthorized access attempts to sandbox folders.
- Patching: Upgrade to Sandboxie version v1.14.6 / 5.69.6 or later as soon as it becomes available.
Long-Term Mitigation:
- Regular Audits: Conduct regular security audits of sandbox environments.
- User Training: Educate users on the risks associated with sandbox environments and best practices for secure usage.
- ACL Management: Regularly review and manage ACLs to ensure they are not being manipulated.
5. Impact on European Cybersecurity Landscape
The vulnerability poses a significant risk to organizations and individuals using Sandboxie for isolation purposes. Unauthorized access to sensitive files can lead to data breaches, intellectual property theft, and other security incidents. Given the widespread use of Sandboxie in various sectors, including finance, healthcare, and government, the impact could be far-reaching.
6. Technical Details for Security Professionals
Technical Analysis:
- File Access: The vulnerability allows reading of files in
C:\Sandbox\UserB\xxxby any authenticated user, bypassing the intended isolation. - ACL Manipulation: The creation of folders with malicious ACLs in
C:\Sandbox\UserAcan lead to persistent unauthorized access, as Sandboxie does not reset these ACLs.
Detection and Response:
- Logging: Enable detailed logging for file access and ACL changes in sandbox directories.
- Intrusion Detection: Implement intrusion detection systems (IDS) to monitor for suspicious activities in sandbox environments.
- Incident Response: Develop an incident response plan specifically for sandbox-related vulnerabilities, including steps for containment, eradication, and recovery.
Conclusion: The vulnerability in Sandboxie is critical and requires immediate attention. Organizations should prioritize patching and implementing robust access controls to mitigate the risk. Regular monitoring and auditing of sandbox environments are essential to detect and respond to any unauthorized access attempts.
References:
By addressing this vulnerability promptly and comprehensively, organizations can significantly reduce the risk of unauthorized access and data breaches, thereby enhancing their overall cybersecurity posture.