CVE-2026-89038 in Cloud for Android
Summary
by MITRE • 09/17/2026
Verizon Cloud for Android (com.vcast.mediamanager) before 26.7.10 contains a path traversal vulnerability that allows co-resident malicious applications to write attacker-controlled bytes outside the intended staging directory by supplying a crafted _display_name value containing path-traversal sequences through exported activities OneTouchUploadActivity and PrintShopCloudActivity. Attackers can exploit the unsanitized filename concatenation in the file-staging sink via ACTION_SEND or ACTION_SEND_MULTIPLE intents to achieve arbitrary file write and inject attacker-controlled content into the authenticated user's Verizon Cloud account without user interaction.
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Analysis
by VulDB Data Team • 09/17/2026
The vulnerability identified in Verizon Cloud for Android prior to version 26.7.10 represents a critical security flaw rooted in improper input validation within exported application components. Specifically, the activities OneTouchUploadActivity and PrintShopCloudActivity are exposed to other applications on the device without adequate sanitization of incoming data parameters. This architectural decision creates an attack surface where co-resident malicious applications can interact with these services directly through Android intents. The core technical failure lies in how the application handles filenames provided via the _display_name extra field during ACTION_SEND or ACTION_SEND_MULTIPLE intent operations. Instead of validating that the filename remains within a designated, secure staging directory, the application concatenates this unsanitized input directly into file paths used for storage operations.
This lack of path normalization allows an attacker to inject standard Unix-style path traversal sequences, such as dot-dot-slash characters, into the _display_name parameter. By doing so, the malicious application can manipulate the resulting file system path to write data outside the intended sandboxed directory structure. This mechanism effectively bypasses the Android security model's expectation that applications operate within isolated storage boundaries. The vulnerability is classified under CWE-22 as Improper Limitation of a Pathname to a Restricted Directory, which highlights the failure to restrict access to resources based on their location relative to an expected root or base directory.
The operational impact of this flaw is significant because it enables arbitrary file writes within the context of the Verizon Cloud application's permissions and authentication state. Since the vulnerability can be triggered without user interaction through intent broadcasts, a malicious app installed alongside Verizon Cloud can silently upload files that are then synchronized to the authenticated user's cloud account. This capability allows attackers to inject attacker-controlled content into the victim's private data store, potentially leading to data integrity compromise or serving as a vector for further exploitation if those uploaded files are processed by other services with higher privileges. The ability to write arbitrary bytes also suggests potential risks related to overwriting existing system or configuration files if path traversal is extended sufficiently deep into the directory hierarchy.
From an offensive security perspective, this vulnerability aligns with MITRE ATT&CK techniques involving local privilege escalation and data staging for persistence or exfiltration preparation. It exemplifies how exported components in Android applications can be abused when input validation is neglected during intent handling. The exploitation does not require root access but relies on the presence of a malicious co-resident application, making it particularly dangerous in shared device environments or enterprise mobile management scenarios where multiple apps may reside on the same OS instance.
Mitigation for this vulnerability requires immediate patching to version 26.7.10 or later, which addresses the input validation logic within the affected activities. Developers must implement strict allow-listing of characters permitted in filenames and enforce canonicalization checks before any file system operations are performed. Additionally, exporting sensitive activities should be minimized, and if necessary, they should require explicit permissions to prevent unauthorized apps from sending intents. Implementing robust path resolution that resolves symbolic links and normalizes directory separators is essential to preventing traversal attacks. Security audits of Android applications must prioritize the review of exported components and their handling of external data sources to ensure compliance with secure coding standards such as OWASP Mobile Application Security Verification Standard guidelines regarding input validation and access control.