CVE-2026-50226: AcerConnect OTA Auth Bypass Vulnerability

CVE-2026-50226 Overview

CVE-2026-50226 affects the AcerConnect OTA (Over-the-Air) application, which ships with hardcoded AES-128-CBC cryptographic keys embedded in the client binary. Attackers extract these static keys and forge authorization credentials for arbitrary International Mobile Equipment Identity (IMEI) numbers. The forged credentials grant unauthorized access to the OTA catalog service, allowing actors to enumerate available firmware items and retrieve protected binaries through pre-signed cloud download links. The flaw is categorized under [CWE-321] Use of Hard-coded Cryptographic Key. Exploitation requires no user interaction and no prior authentication, and the attack vector is network-based.

Critical Impact

Attackers can forge authorization tokens for any IMEI, enumerate the OTA catalog, and download protected firmware artifacts from pre-signed cloud URLs without authentication.

Affected Products

• AcerConnect OTA application
• Acer devices relying on the AcerConnect OTA update service
• Cloud-hosted firmware catalog accessed by AcerConnect OTA clients

Discovery Timeline

• 2026-06-04 - CVE-2026-50226 published to the National Vulnerability Database
• 2026-06-04 - Last updated in NVD database

Technical Details for CVE-2026-50226

Vulnerability Analysis

The AcerConnect OTA client embeds a fixed AES-128-CBC key and initialization vector used to generate authorization credentials sent to the firmware catalog service. Because the same key material ships in every installation, an attacker who extracts it from one client can mint valid encrypted tokens for any IMEI value. The backend service trusts these tokens as proof of device identity and authorization. Once accepted, the server returns catalog listings and issues pre-signed cloud storage URLs pointing to firmware binaries that were intended to be access-controlled. Researchers categorize this as a cryptographic design failure rather than an implementation bug, since the cipher itself functions correctly but the key management model treats a client-side secret as a server-side trust anchor.

Root Cause

The root cause is the use of a hard-coded symmetric cryptographic key inside a distributed client application [CWE-321]. The AES-128-CBC key cannot be rotated per device, cannot be protected against reverse engineering, and provides no cryptographic binding between the requesting endpoint and the IMEI it claims to represent. Any party with access to the client binary can recover the key through static analysis or memory inspection.

Attack Vector

An attacker first obtains the AcerConnect OTA client and extracts the embedded AES-128-CBC key through reverse engineering. The attacker then constructs an authorization payload containing a chosen IMEI, encrypts it with the recovered key, and submits it to the OTA backend over the network. The server validates the ciphertext, accepts the forged identity, and returns catalog metadata along with pre-signed download URLs. The attacker downloads the protected firmware binaries directly from cloud storage. No physical access, user interaction, or prior credentials are required. Refer to the Acer Community Knowledge Base Article for vendor-provided technical context.

Detection Methods for CVE-2026-50226

Indicators of Compromise

• Unusual volume of OTA catalog requests originating from non-mobile network ranges or cloud hosting providers.
• Repeated catalog queries cycling through sequential or randomized IMEI values from a single source address.
• Anomalous downloads of firmware binaries from pre-signed cloud storage URLs without matching device check-in telemetry.

Detection Strategies

• Correlate OTA catalog requests with legitimate device telemetry to identify IMEI values that have no corresponding active device record.
• Inspect server logs for authorization tokens that decrypt successfully but are tied to IMEI values never previously observed in production.
• Monitor egress from cloud storage buckets hosting firmware for download patterns inconsistent with normal device update cycles.

Monitoring Recommendations

• Enable rate limiting and per-source-IP quotas on the OTA catalog endpoint and alert on threshold breaches.
• Log every issuance of pre-signed cloud URLs along with the requesting IMEI, source IP, and User-Agent for retrospective analysis.
• Forward OTA service and cloud storage access logs to a centralized analytics platform for cross-source correlation and anomaly detection.

How to Mitigate CVE-2026-50226

Immediate Actions Required

• Apply vendor-supplied updates to the AcerConnect OTA application as soon as Acer publishes a patched build.
• Rotate cryptographic material on the server side and invalidate any tokens generated with the legacy hard-coded key.
• Restrict pre-signed cloud storage URL lifetimes to the shortest viable duration and bind them to source IP where feasible.
• Audit firmware download logs to identify any unauthorized retrievals that may have already occurred.

Patch Information

Acer has published technical guidance through the Acer Community Knowledge Base Article. Administrators and device owners should consult this advisory for the affected versions and remediation steps. No additional vendor advisory URLs are listed in the current CVE record.

Workarounds

• Add server-side authentication that does not rely solely on client-supplied encrypted IMEI tokens, such as device certificates or mutual TLS.
• Implement server-side authorization checks that validate the IMEI against an enrolled device registry before issuing pre-signed URLs.
• Restrict access to the OTA catalog endpoint by network segmentation or allowlisting trusted mobile carrier ranges where operationally feasible.

# Configuration example
# Example NGINX rate limit and IMEI allowlist for OTA catalog endpoint
limit_req_zone $binary_remote_addr zone=ota_catalog:10m rate=5r/m;

location /ota/catalog {
    limit_req zone=ota_catalog burst=10 nodelay;
    auth_request /internal/validate-device-cert;
    proxy_pass http://ota_backend;
}