CVE-2021-39764 in Android
Summary
by MITRE • 03/30/2022
In Settings, there is a possible way to display an incorrect app name due to improper input validation. This could lead to local escalation of privilege via app spoofing with no additional execution privileges needed. User interaction is needed for exploitation.Product: AndroidVersions: Android-12LAndroid ID: A-170642995
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Analysis
by VulDB Data Team • 04/02/2022
The vulnerability identified as CVE-2021-39764 resides within the Android Settings application and represents a critical security flaw that enables local privilege escalation through application spoofing techniques. This issue manifests when the system fails to properly validate input data during the display of application names, creating an opportunity for malicious actors to manipulate how applications appear within the user interface. The vulnerability specifically affects Android 12L and represents a significant concern for system integrity and user trust in application identification mechanisms.
The technical root cause of this vulnerability stems from inadequate input validation procedures within the Settings application's handling of application metadata. When applications are registered or updated within the system, the validation process fails to properly sanitize or verify the input data that determines how application names are displayed. This improper validation creates a condition where attacker-controlled data can influence the presentation layer of the application interface, potentially allowing for the display of misleading application information. The flaw operates at the user interface level where application names are rendered, making it particularly dangerous as it can deceive users into interacting with malicious applications under false pretenses.
From an operational perspective, this vulnerability enables a sophisticated attack vector that requires only user interaction to achieve privilege escalation. An attacker can craft a malicious application that, when installed or activated, displays a spoofed application name that mimics a legitimate system application or trusted third-party application. The attack chain begins with the user encountering the spoofed application name within the Settings interface, potentially leading them to perform actions that would normally be restricted to privileged applications. This exploitation path does not require additional execution privileges, making it particularly concerning as it can be leveraged by attackers with minimal initial access. The vulnerability essentially allows for the creation of a deceptive environment where users cannot reliably distinguish between legitimate and malicious applications based on their displayed names alone.
The security implications extend beyond simple spoofing, as this vulnerability can facilitate more complex attack scenarios including credential theft, unauthorized system modifications, and privilege escalation to root-level access. The attack leverages the principle of user deception through interface manipulation, a technique that aligns with attack patterns described in the MITRE ATT&CK framework under the T1546 category for privilege escalation. The vulnerability also relates to CWE-20, which describes improper input validation as a fundamental weakness that can lead to various security issues including injection attacks and user interface manipulation. This flaw represents a significant concern for Android's security model, as it undermines the trust relationships between users and the applications they interact with, potentially allowing for the execution of malicious code under the guise of legitimate system functions.
Mitigation strategies for CVE-2021-39764 should focus on implementing robust input validation mechanisms within the Settings application and related system components. System administrators and security teams should prioritize applying the latest Android security patches and updates that address this specific vulnerability. The mitigation approach should include strengthening the validation of application metadata and ensuring that all application name displays are verified against trusted sources before being rendered to users. Additionally, implementing runtime monitoring for suspicious application name changes and user interface manipulations can help detect potential exploitation attempts. Organizations should also consider deploying application whitelisting policies and enhanced user education to reduce the risk of falling victim to spoofing attacks. The vulnerability highlights the critical importance of input validation in security-sensitive components and underscores the need for comprehensive security testing of user interface elements that handle external data inputs.