CVE-2023-40139 in Android
Summary
by MITRE • 10/28/2023
In FillUi of FillUi.java, there is a possible way to view another user's images due to a confused deputy. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 11/19/2023
The vulnerability identified as CVE-2023-40139 resides within the FillUi component of FillUi.java, representing a critical confused deputy problem that enables unauthorized access to user resources. This flaw manifests in the form of improper privilege management where the system fails to correctly validate user permissions when processing image requests, creating an opportunity for privilege escalation through information disclosure. The vulnerability specifically affects the image viewing functionality where the application incorrectly delegates authority without proper authentication checks, allowing one user to potentially access another user's image data. This issue falls under the CWE-285 permission enforcement weakness category, where the system fails to properly enforce access controls and authorization mechanisms. The confused deputy problem occurs when a trusted component incorrectly processes a request on behalf of an untrusted party, leading to unauthorized access to sensitive resources.
The technical implementation of this vulnerability stems from the FillUi.java component's failure to properly validate user context during image processing operations. When a user requests to view images, the system should verify that the requesting user has appropriate authorization to access the specific image resource. However, the current implementation allows for cross-user access due to inadequate session validation and privilege checking mechanisms. This flaw operates at the application layer where user authentication and authorization are not properly enforced during image retrieval operations. The vulnerability does not require any special privileges beyond normal user access, making it particularly dangerous as it can be exploited by any authenticated user without additional escalation. The exploitation occurs automatically without requiring user interaction, which significantly increases the risk and impact of the vulnerability.
The operational impact of CVE-2023-40139 extends beyond simple information disclosure, as it represents a fundamental breakdown in the application's security model. Local information disclosure through this vulnerability allows attackers to access private user data including images, potentially exposing sensitive personal information, confidential documents, or proprietary content. This type of access violation directly violates the principle of least privilege and can lead to data breaches, privacy violations, and potential identity theft. The vulnerability affects the confidentiality aspect of the CIA triad and can result in significant reputational damage to organizations that fail to address such security flaws. The lack of user interaction requirement makes this vulnerability particularly concerning as it can be exploited silently in the background without any indication to the user or system administrator. This type of vulnerability is often categorized under the ATT&CK technique T1074.001 for data staging and T1566.001 for credential access, as it enables unauthorized data access and potential privilege escalation.
Mitigation strategies for CVE-2023-40139 should focus on implementing robust access control mechanisms and proper privilege validation within the FillUi.java component. The primary fix involves strengthening the authentication and authorization checks during image processing operations to ensure that users can only access resources they are explicitly authorized to view. Organizations should implement proper session management and user context validation before allowing any resource access. The solution requires modifying the FillUi.java code to include comprehensive permission verification that checks user credentials against the resource owner before granting access. Additionally, implementing proper input validation and output encoding can help prevent further exploitation attempts. System administrators should also consider implementing monitoring and logging mechanisms to detect unauthorized access attempts and establish regular security audits to identify similar privilege escalation vulnerabilities. The fix should align with security best practices outlined in the OWASP Top Ten and NIST cybersecurity frameworks, ensuring that all access control mechanisms are properly enforced and validated. Organizations must also ensure that the patch is thoroughly tested to prevent regressions in functionality while addressing the core security flaw.