CVE-2026-8077: CashDro 3 Privilege Escalation Vulnerability

CVE-2026-8077 Overview

CVE-2026-8077 is a broken access control vulnerability in the CashDro 3 web administration panel, version 24.01.00.26. The backend enforces no authorization checks, delegating all access control decisions to the frontend client. An authenticated attacker with low privileges can modify the binary string in the Permissions field of a JSON response to escalate to full administrative access. The flaw maps to CWE-862: Missing Authorization and allows complete compromise of cash management functions on affected devices.

Critical Impact

A low-privileged user can bypass every role-based restriction and gain full administrative control of the CashDro 3 device, including operations tied to physical cash handling.

Affected Products

• CashDro 3 web administration panel, version 24.01.00.26
• CashDro 3 cash management devices running the affected firmware
• Deployments exposing the administration panel over the network

Discovery Timeline

• 2026-05-07 - Technical analysis published by IT Resit security research team
• 2026-05-08 - INCIBE CERT publishes coordinated vulnerability notice for multiple CashDro 3 issues
• 2026-05-08 - CVE-2026-8077 published to NVD
• 2026-05-08 - Last updated in NVD database

Technical Details for CVE-2026-8077

Vulnerability Analysis

The CashDro 3 administration panel implements a client/server split in which the server returns user context, including permissions, as part of a JSON response. The backend trusts the frontend to enforce role boundaries derived from that response. No server-side authorization check validates whether the requesting session is allowed to invoke administrative endpoints.

The Permissions field is represented as a binary string. Each bit corresponds to a specific capability within the application. By flipping bits to 1, an attacker can advertise privileges the server never granted. Because the backend does not re-validate the claim, every subsequent API request is processed as if the attacker held those rights.

This design defect categorizes the issue as broken access control rather than a memory or injection bug. Exploitation does not require crafted payloads or specialized tooling. An authenticated low-privilege account is the only prerequisite.

Root Cause

The root cause is missing server-side enforcement of authorization decisions (CWE-862). Permission state is communicated to the client and then re-read or re-submitted without server-side verification, allowing the client to dictate its own access level.

Attack Vector

The attack vector is network-based and requires a valid low-privilege session on the administration panel. An attacker intercepts the JSON response containing the Permissions bitmask, sets all bits to enable every capability, and proceeds to call administrative endpoints. See the IT Resit technical write-up and the INCIBE CERT advisory for full reproduction details.

// Conceptual representation - no verified PoC code published
// Original server response to a low-privilege user:
// { "user": "cashier", "Permissions": "0000000000000001" }
//
// Tampered client state submitted to administrative endpoints:
// { "user": "cashier", "Permissions": "1111111111111111" }
//
// Backend processes administrative API calls without re-checking authorization.

Detection Methods for CVE-2026-8077

Indicators of Compromise

• Administrative API calls originating from accounts provisioned with non-administrative roles.
• HTTP requests or responses to the CashDro 3 panel that include modified Permissions binary strings.
• New administrator accounts, configuration changes, or cash dispensing operations performed by historically low-privilege users.
• Session activity from unexpected source IP addresses outside normal point-of-sale network segments.

Detection Strategies

• Compare role assignments in the identity store against the actions actually performed via the administration panel, alerting on privilege mismatch.
• Inspect HTTP traffic for JSON payloads containing the Permissions field with values inconsistent with the authenticated user's assigned role.
• Baseline administrative endpoint usage per user account and alert on first-time access patterns.

Monitoring Recommendations

• Forward CashDro 3 application and web server logs to a centralized log platform for correlation with identity events.
• Monitor for repeated requests to administrative endpoints by accounts that previously only invoked operator-level functions.
• Alert on configuration export, user creation, and cash operation events tied to non-administrator identities.

How to Mitigate CVE-2026-8077

Immediate Actions Required

• Contact Cashlogy or your CashDro 3 reseller for a fixed firmware build that enforces server-side authorization.
• Restrict network access to the web administration panel to trusted management VLANs and management workstations only.
• Rotate credentials for all CashDro 3 panel accounts and remove unused or shared accounts.
• Review recent administrative activity for unauthorized configuration or cash handling operations.

Patch Information

No specific patched version is listed in the NVD entry at publication. Refer to the INCIBE CERT advisory for vendor coordination details and obtain a remediated firmware release directly from the manufacturer before redeploying the panel on production networks.

Workarounds

• Place the CashDro 3 administration panel behind a reverse proxy or VPN that enforces additional authentication and IP allowlisting.
• Disable or block remote access to the administration interface where business operations permit.
• Apply strict network segmentation between cashier workstations and the device management interface.
• Audit accounts regularly and apply least-privilege role assignments until a vendor patch is deployed.

# Example: restrict access to the CashDro 3 admin panel to a management subnet
# (adjust interface, subnet, and panel port to match the environment)
iptables -A INPUT -p tcp --dport 443 -s 10.10.20.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP