CVE-2026-21017 Overview
CVE-2026-21017 is a medium-severity vulnerability in Samsung Android's SecTelephonyProvider component. The flaw stems from improper handling of insufficient privileges, allowing local attackers to access privileged files on affected devices. Samsung addressed the issue in the SMR Jun-2026 Release 1 security maintenance release.
The vulnerability impacts Samsung Android versions 14.0, 15.0, and 16.0 across multiple prior SMR releases. Exploitation requires local access and user interaction, limiting remote attack scenarios. The weakness is categorized under [CWE-Other] per NVD classification.
Critical Impact
A local attacker with user interaction can read privileged files managed by SecTelephonyProvider, exposing telephony-related data that should be restricted to higher-privileged components.
Affected Products
- Samsung Android 14.0 (releases prior to SMR Jun-2026 Release 1)
- Samsung Android 15.0 (releases prior to SMR Jun-2026 Release 1)
- Samsung Android 16.0 (releases prior to SMR Jun-2026 Release 1)
Discovery Timeline
- 2026-06-05 - CVE-2026-21017 published to NVD
- 2026-06-06 - Last updated in NVD database
- June 2026 - Samsung releases SMR Jun-2026 Release 1 security patch
Technical Details for CVE-2026-21017
Vulnerability Analysis
The vulnerability resides in SecTelephonyProvider, a Samsung-specific content provider component on Android that exposes telephony-related data such as call logs, SMS messages, carrier configuration, and subscription metadata. The component fails to correctly validate the privilege level of the calling process before granting access to protected resources.
When a local application invokes the provider, the missing or insufficient privilege check allows it to retrieve files that should be reserved for system or signature-level callers. The vulnerability is classified as improper handling of insufficient privileges, a subclass of broken access control. The flaw is exploited through standard Android inter-process communication channels.
Root Cause
The root cause is a missing or incomplete permission enforcement path inside SecTelephonyProvider. Privileged file paths exposed by the provider lack the corresponding signature or signatureOrSystem protection-level checks before file access is performed. As a result, an unprivileged application can request resources without being challenged by Android's permission framework.
Attack Vector
Exploitation requires a malicious application installed on the device and limited user interaction. The application targets SecTelephonyProvider through Android IPC, requesting URIs that map to privileged files. Because the provider does not enforce the expected permission gate, the call succeeds and returns sensitive data to the unprivileged caller. The attacker gains read access to telephony files but cannot directly achieve code execution or remote compromise.
No public proof-of-concept code has been released for CVE-2026-21017. Refer to the Samsung Mobile Security Update for vendor-supplied technical details.
Detection Methods for CVE-2026-21017
Indicators of Compromise
- Unexpected applications issuing queries against content:// URIs associated with SecTelephonyProvider.
- Installed packages requesting telephony-related permissions outside their declared functional scope.
- Anomalous file reads of telephony data stores by non-system UIDs in device logs.
Detection Strategies
- Inspect mobile device logs and Mobile Threat Defense telemetry for unauthorized access to telephony providers.
- Monitor application install events on managed Samsung devices for sideloaded APKs from untrusted sources.
- Audit installed applications for those requesting access to telephony content providers without clear business justification.
Monitoring Recommendations
- Track Samsung firmware build numbers across the fleet to identify devices missing SMR Jun-2026 Release 1.
- Forward mobile EMM/MDM compliance events into a centralized SIEM for trend analysis.
- Alert on devices that delay applying monthly Samsung security maintenance releases beyond defined SLAs.
How to Mitigate CVE-2026-21017
Immediate Actions Required
- Apply the Samsung SMR Jun-2026 Release 1 update to all affected Samsung Android 14, 15, and 16 devices.
- Enforce MDM policies that block installation of applications from untrusted sources on managed devices.
- Review installed applications and remove those with no legitimate need for telephony provider access.
Patch Information
Samsung released the official fix in the SMR Jun-2026 Release 1 maintenance update. Patch availability varies by device model and carrier. Refer to the Samsung Mobile Security Update bulletin for June 2026 for the authoritative list of patched builds and rollout details.
Workarounds
- Restrict device users from sideloading applications until the SMR Jun-2026 Release 1 patch is applied.
- Use enterprise mobility management to enforce allowlists of approved applications on Samsung devices.
- Educate users to avoid granting unnecessary permissions and to ignore prompts from unverified apps, since exploitation requires user interaction.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
