CVE-2025-13806: NutzBoot Auth Bypass Vulnerability

CVE-2025-13806 Overview

A security vulnerability has been detected in nutzam NutzBoot up to version 2.6.0-SNAPSHOT. This impacts an unknown function of the file nutzboot-demo/nutzboot-demo-simple/nutzboot-demo-simple-web3j/src/main/java/io/nutz/demo/simple/module/EthModule.java of the component Transaction API. The manipulation of the argument from/to/wei leads to improper authorization. Remote exploitation of the attack is possible. The exploit has been disclosed publicly and may be used.

Critical Impact
This improper authorization vulnerability (CWE-266) allows remote attackers to manipulate transaction parameters without proper authorization checks, potentially leading to unauthorized cryptocurrency transfers in applications using the affected NutzBoot Web3j demo module.

Affected Products

nutzam NutzBoot up to version 2.6.0-SNAPSHOT
NutzBoot Web3j Demo Module (EthModule.java)
Applications using the affected Transaction API component

Discovery Timeline

December 1, 2025 - CVE-2025-13806 published to NVD
December 1, 2025 - Last updated in NVD database

Technical Details for CVE-2025-13806

Vulnerability Analysis

CVE-2025-13806 is classified as an Improper Authorization vulnerability (CWE-266: Incorrect Privilege Assignment) affecting the Transaction API component within the NutzBoot framework. The vulnerability carries a CVSS 4.0 score of 6.9 (Medium) with the vector string CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X.

The vulnerability exists in the EthModule.java file, which handles Ethereum transaction operations. The affected parameters include from, to, and wei arguments that can be manipulated by attackers to bypass authorization controls.

According to EPSS (Exploit Prediction Scoring System) data from December 16, 2025, this vulnerability has an EPSS score of 0.053% (16.78th percentile), indicating a relatively low probability of exploitation in the wild.

Root Cause

The root cause of this vulnerability is the lack of proper authorization checks when processing transaction requests through the Transaction API. The EthModule.java component fails to adequately validate whether the requesting user has permission to initiate transactions with the specified parameters. This incorrect privilege assignment allows unauthorized manipulation of transaction details including source addresses, destination addresses, and transfer amounts.

Attack Vector

The attack vector for this vulnerability is network-based, allowing remote exploitation without user interaction. An attacker can exploit this vulnerability by sending crafted requests to the Transaction API endpoint with manipulated from, to, and wei parameters.

The vulnerability mechanism involves bypassing authorization controls in the Ethereum transaction handling logic. When a transaction request is received, the application fails to verify that the requesting entity has proper authorization to initiate transfers from the specified source address or to the specified amounts. This allows an attacker to potentially redirect funds or initiate unauthorized transfers.

For technical details and proof-of-concept information, refer to the security advisory on GitHub.

Detection Methods for CVE-2025-13806

Indicators of Compromise

Unusual transaction patterns in Web3j/Ethereum transaction logs
Unexpected API requests to the Transaction API endpoint with modified from, to, or wei parameters
Authentication anomalies or requests bypassing normal authorization flows

Detection Strategies

Organizations using NutzBoot with the Web3j demo module should implement the following detection strategies:

API Request Monitoring: Monitor incoming requests to the Transaction API for anomalous parameter values, particularly for the from, to, and wei fields.
Authorization Log Analysis: Review authorization logs for failed or suspicious authorization attempts related to transaction operations.
Transaction Audit Trail: Implement comprehensive logging of all Ethereum transactions processed through the application to detect unauthorized transfers.
Source Code Review: Audit the EthModule.java file and related transaction handling code for authorization bypass vulnerabilities.

Monitoring Recommendations

Security teams should implement real-time monitoring for:

API endpoint access patterns targeting /api/eth/ or similar transaction-related endpoints
Parameter tampering attempts in transaction requests
Unusual transaction volumes or values processed through the application
Network traffic analysis for exploitation attempts targeting the vulnerable component

SentinelOne customers can leverage behavioral analysis capabilities to detect suspicious API interactions and potential authorization bypass attempts within their environment.

How to Mitigate CVE-2025-13806

Immediate Actions Required

Assess whether your deployment uses the vulnerable EthModule.java component from the NutzBoot Web3j demo
Restrict network access to the Transaction API endpoint using firewall rules or network segmentation
Implement additional authorization checks before processing any transaction requests

Patch Information

As of the last update on December 1, 2025, no official patch has been released by the vendor. Organizations should monitor the official NutzBoot repository and security advisories for patch availability. The vulnerability affects versions up to 2.6.0-SNAPSHOT.

Additional information can be found at:

Workarounds

Until an official patch is available, organizations should implement the following workarounds:

Disable the vulnerable component: If the Web3j demo transaction functionality is not required in production, disable or remove the EthModule.java component entirely.
Implement custom authorization: Add manual authorization checks before processing any transaction requests, validating that the requesting user has permission to perform the specified operation.
Network-level restrictions: Limit access to the Transaction API to trusted internal networks only.
Input validation: Implement strict input validation for the from, to, and wei parameters to ensure they conform to expected formats and authorized values.

Organizations should prioritize upgrading to a patched version when one becomes available from the NutzBoot project maintainers.