CVE-2025-26427 Overview
CVE-2025-26427 is a path traversal vulnerability [CWE-24] affecting Google Android. The flaw exists in multiple locations within the Android framework and the DownloadProvider component. Improper validation of file paths allows a local application to access files under the protected Android/data directory belonging to other applications. Successful exploitation leads to local escalation of privilege without requiring additional execution permissions, though user interaction is required. Google addressed the issue in the Android Security Bulletin dated May 1, 2025.
Critical Impact
A malicious local application can traverse outside its sandbox and read or write to another application's private Android/data directory, breaking the app-isolation model that Android relies on for confidentiality and integrity.
Affected Products
- Google Android 13.0
- Google Android 14.0
- Android framework and DownloadProvider components prior to the May 2025 security patch level
Discovery Timeline
- 2025-09-04 - CVE-2025-26427 published to the National Vulnerability Database (NVD)
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-26427
Vulnerability Analysis
The vulnerability is a path traversal issue classified under [CWE-24] (Path Traversal: ../filedir). It resides in multiple Android system components, including the framework code in platform/frameworks/base and the DownloadProvider in platform/packages/providers/DownloadProvider. Android normally isolates each application's data under /storage/emulated/0/Android/data/<package_name>/. The vulnerable code paths accept file identifiers or destination paths that were not fully normalized before being resolved against a base directory. An attacker-controlled input containing traversal sequences causes the resolved path to escape the intended sandbox root.
Exploitation requires local access and user interaction, typically in the form of installing or launching a malicious application and approving a normal operation such as a download or file share. The scope remains unchanged, and the resulting access is limited to confidentiality and integrity of files inside Android/data rather than full system compromise.
Root Cause
The root cause is missing or incomplete canonicalization of user-controlled path segments before they are joined with a trusted base directory. When the composed path is passed to file I/O APIs, sequences such as .. allow the resolved path to point at another package's private data directory. Patches applied in commits 4af5db76f25348849252e0b8a08f4a517ef842b7 (framework) and 5acd646e0cf63e2c9c0862da7e03531ef0074394 (DownloadProvider) enforce stricter validation so that the final path stays within the expected root.
Attack Vector
The attack vector is local. A malicious application installed on the device supplies crafted path or URI values to the vulnerable framework or DownloadProvider interfaces. The user must perform an action such as accepting a download, sharing a file, or interacting with a prompt for the vulnerable code path to execute. On success, the attacker gains read or write access to files owned by a different application under Android/data, which can be leveraged to exfiltrate sensitive data or plant malicious content that another app will later load.
No public proof-of-concept exploit or CISA KEV listing is currently associated with this CVE. See the Android Security Bulletin May 2025 for authoritative technical details.
Detection Methods for CVE-2025-26427
Indicators of Compromise
- Presence of .. sequences or encoded traversal patterns (%2e%2e, ..%2f) in filenames, destination paths, or content URIs handled by DownloadProvider.
- Unexpected file reads or writes under Android/data/<other_package>/ initiated by an unrelated third-party application.
- Newly installed applications requesting broad storage or download-related permissions immediately before anomalous file access.
Detection Strategies
- Inspect application manifests and runtime behavior for use of the DownloadManager API with destination paths containing traversal characters.
- Review mobile threat defense telemetry for cross-package file access events on Android 13 and Android 14 devices missing the May 2025 patch level.
- Perform static analysis of third-party APKs for suspicious construction of file paths that concatenate untrusted input with Android/data.
Monitoring Recommendations
- Track the reported Android security patch level on managed devices and alert when devices remain below 2025-05-01.
- Monitor enterprise mobility management (EMM) inventory for sideloaded or unknown-source applications on affected OS versions.
- Correlate download activity from DownloadProvider with subsequent file access outside the requesting app's sandbox.
How to Mitigate CVE-2025-26427
Immediate Actions Required
- Apply the Android security patch level 2025-05-01 or later to all Android 13 and Android 14 devices.
- Enforce EMM or MDM policies that block installation of applications from unknown sources on unpatched devices.
- Audit installed applications and remove any that request unnecessary storage or download permissions from untrusted publishers.
Patch Information
Google fixed CVE-2025-26427 in the May 2025 Android Security Bulletin. The relevant source changes are available in the Android Framework Code Changes and the DownloadProvider Code Update. Device vendors distribute the fix through their scheduled OTA updates aligned with the May 2025 patch level.
Workarounds
- Restrict installation to Google Play and vetted enterprise app catalogs until the patch is deployed.
- Disable or restrict use of high-risk applications that heavily interact with DownloadProvider on unpatched devices.
- Educate users to decline prompts from unfamiliar applications requesting downloads or file operations, since exploitation requires user interaction.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.