CVE-2023-28725 – This vulnerability allows remote attackers to e... (How to Fix)

Q: What is the severity of CVE-2023-28725?

CVE-2023-28725 has a CVSS score of 9.1 (CRITICAL). This vulnerability allows remote attackers to execute arbitrary Java code on General Bytes Crypto Application Server by uploading malicious applications to a specific directory. It affects General Bytes BATM devices running CAS versions before the fix, enabling complete system compromise. Attackers exploited this in March 2023 to steal over $1.6 million from cryptocurrency ATMs.

📋 TL;DR

This vulnerability allows remote attackers to execute arbitrary Java code on General Bytes Crypto Application Server by uploading malicious applications to a specific directory. It affects General Bytes BATM devices running CAS versions before the fix, enabling complete system compromise. Attackers exploited this in March 2023 to steal over $1.6 million from cryptocurrency ATMs.

💻 Affected Systems

Products:

General Bytes Crypto Application Server (CAS)
General Bytes BATM devices

Versions: CAS 20230120 and earlier versions, specifically before 20221118.48 and 20230120.44

Operating Systems: Not specified, but likely Linux-based given Java deployment

Default Config Vulnerable: ⚠️ Yes

Notes: Distributed with General Bytes BATM devices; exploited in the wild in March 2023.

📦 What is this software?

Crypto Application Server by Generalbytes

View all CVEs affecting Crypto Application Server →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete system takeover, theft of all cryptocurrency funds, installation of persistent backdoors, and lateral movement to other systems.

🟠

Likely Case

Theft of cryptocurrency funds, installation of malware for future attacks, and disruption of ATM operations.

🟢

If Mitigated

Limited impact with proper network segmentation and access controls, potentially only service disruption.

🌐 Internet-Facing: HIGH - Exploited remotely in the wild without authentication, affecting internet-facing ATM systems.

🏢 Internal Only: HIGH - Even internal systems are vulnerable to the same attack vector if accessible.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: CONFIRMED

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Actively exploited in the wild as confirmed by vendor and news reports; involves simple file upload to specific directory.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 20221118.48 and 20230120.44

Vendor Advisory: https://generalbytes.atlassian.net/wiki/spaces/ESD/pages/2885222430/Security+Incident+March+17-18th+2023

Restart Required: Yes

Instructions:

1. Download the patched version from General Bytes. 2. Stop the CAS service. 3. Install the update. 4. Restart the service. 5. Verify the version is updated.

🔧 Temporary Workarounds

Restrict access to deployment directory

linux

Block unauthorized access to the /batm/app/admin/standalone/deployments directory using firewall rules or access controls.

# Example: iptables rule to block external access to port/directory
iptables -A INPUT -p tcp --dport [CAS_PORT] -j DROP

Disable unnecessary services

linux

Disable or restrict the CAS deployment service if not essential for operations.

systemctl stop [CAS_SERVICE_NAME]
systemctl disable [CAS_SERVICE_NAME]

🧯 If You Can't Patch

Isolate affected systems from the internet and internal networks using firewall rules.
Implement strict access controls and monitoring for the /batm/app/admin/standalone/deployments directory.

🔍 How to Verify

Check if Vulnerable:

Check CAS version; if earlier than 20221118.48 or 20230120.44, the system is vulnerable.

Check Version:

Check CAS interface or configuration files for version information; specific command depends on installation.

Verify Fix Applied:

Confirm CAS version is 20221118.48 or 20230120.44 or later, and test that unauthorized file uploads to the deployment directory are blocked.

📡 Detection & Monitoring

Log Indicators:

Unauthorized file uploads to /batm/app/admin/standalone/deployments
Unexpected Java process executions
Failed authentication attempts to CAS admin interface

Network Indicators:

Unusual outbound connections from CAS system
Traffic to known malicious IPs

SIEM Query:

Example: search 'file_upload' AND path:'/batm/app/admin/standalone/deployments' OR 'CAS' AND 'unauthorized_access'

📊 Metadata

CVE ID: CVE-2023-28725

CVSS v3 Score: 9.1 (CRITICAL)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CWE: CWE-434

Published: March 22, 2023

Last Updated: February 26, 2025

🔗 References

https://arstechnica.com/information-technology/2023/03/hackers-drain-bitcoin-atms-of-1-5-million-by-exploiting-0-day-bug/ Press/Media Coverage
https://generalbytes.atlassian.net/wiki/spaces/ESD/pages/2885222430/Security+Incident+March+17-18th+2023 Exploit,Vendor Advisory
https://generalbytes.atlassian.net/wiki/spaces/ESD/pages/951418958/Update+CAS Mitigation
https://twitter.com/generalbytes/status/1637192687160897537 Issue Tracking
https://web3isgoinggreat.com/single/general-bytes-crypto-atms-exploited-for-over-1-6-million Third Party Advisory
https://www.bleepingcomputer.com/news/security/general-bytes-bitcoin-atms-hacked-using-zero-day-15m-stolen/ Press/Media Coverage
https://www.generalbytes.com/en/support/changelog Release Notes
https://arstechnica.com/information-technology/2023/03/hackers-drain-bitcoin-atms-of-1-5-million-by-exploiting-0-day-bug/ Press/Media Coverage
https://generalbytes.atlassian.net/wiki/spaces/ESD/pages/2885222430/Security+Incident+March+17-18th+2023 Exploit,Vendor Advisory
https://generalbytes.atlassian.net/wiki/spaces/ESD/pages/951418958/Update+CAS Mitigation
https://twitter.com/generalbytes/status/1637192687160897537 Issue Tracking
https://web3isgoinggreat.com/single/general-bytes-crypto-atms-exploited-for-over-1-6-million Third Party Advisory
https://www.bleepingcomputer.com/news/security/general-bytes-bitcoin-atms-hacked-using-zero-day-15m-stolen/ Press/Media Coverage
https://www.generalbytes.com/en/support/changelog Release Notes

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