CVE-2026-50207: System Binder Privilege Escalation Flaw

CVE-2026-50207 Overview

CVE-2026-50207 is a high-severity local vulnerability where the system Binder boundary accepts unverified pass-through AT commands. Local applications can issue arbitrary AT commands to the baseband, allowing them to read baseband files or disable cellular connectivity. The flaw stems from missing input validation and improper path handling at the inter-process communication (IPC) boundary, classified as [CWE-22] Path Traversal. Exploitation requires only local access and low privileges, with no user interaction.

Critical Impact
A low-privileged local application can read sensitive baseband files and disable cellular connectivity, undermining device confidentiality, integrity, and availability of mobile communications.

Affected Products

Mobile devices exposing AT command pass-through via the system Binder interface
Baseband modem subsystems reachable through the affected Binder service
Downstream OEM builds that inherit the unverified pass-through path

Discovery Timeline

2026-06-04 - CVE-2026-50207 published to NVD
2026-06-04 - Last updated in NVD database

Technical Details for CVE-2026-50207

Vulnerability Analysis

The vulnerability resides at the system Binder boundary that brokers AT command requests between userspace applications and the baseband processor. The boundary forwards caller-supplied AT command strings to the modem without verifying the command set, target file paths, or required privileges. A local application can therefore issue commands that traverse paths into baseband storage or that toggle radio state. Because the Binder service exposes this functionality to standard application contexts, an attacker does not need root or signature-level access. The result is unauthorized file disclosure from the baseband and a usable denial-of-service primitive against cellular connectivity.

Root Cause

The root cause is missing allow-list validation and path canonicalization on AT command payloads received over Binder. [CWE-22] applies because file-targeting AT commands accept relative or traversal sequences that escape the intended baseband resource scope.

Attack Vector

The attack vector is local. A malicious or compromised application installed on the device opens the Binder interface, crafts AT command strings, and submits them through the pass-through API. The baseband processes the commands as if they originated from a trusted source. No additional authentication, prompt, or user interaction is required.

No verified proof-of-concept code is publicly available. Refer to the Acer Community Knowledge Base Article for vendor context.

Detection Methods for CVE-2026-50207

Indicators of Compromise

Unexpected loss of cellular signal or radio state changes correlated with third-party application activity
Application processes invoking the AT command Binder interface outside of telephony stack components
Read accesses to baseband file paths originating from non-system UIDs

Detection Strategies

Audit Binder transactions to the telephony or RIL service for callers that are not part of the platform telephony stack
Inspect installed applications for permissions or API usage targeting AT command interfaces
Correlate cellular state transitions (radio off, SIM reset) with foreground or background application events

Monitoring Recommendations

Enable telephony subsystem logging and retain modem state change events for forensic review
Monitor for repeated AT command submissions from a single application UID within short time windows
Alert on file read operations targeting baseband storage paths from non-privileged contexts

How to Mitigate CVE-2026-50207

Immediate Actions Required

Restrict installation of untrusted applications on affected devices until a vendor patch is applied
Remove or disable applications that request access to telephony or AT command interfaces without a clear business need
Apply OEM and carrier security updates as soon as they are published for the affected platform

Patch Information

No specific patch identifier is listed in the published advisory. Consult the Acer Community Knowledge Base Article and your device OEM for firmware updates that enforce validation on AT command pass-through at the Binder boundary.

Workarounds

Enforce application allow-listing through mobile device management (MDM) to block untrusted installs
Disable the AT command pass-through Binder service on managed devices where vendor configuration permits
Limit physical and logical access to the device, since the attack vector is local

bash

# Configuration example: MDM policy snippet to block untrusted sources
adb shell settings put global install_non_market_apps 0
adb shell pm disable-user --user 0 <package.providing.at.passthrough>