CVE-2025-6749: bicycleSharingServer SQL Injection Vulnerability

CVE-2025-6749 Overview

CVE-2025-6749 is a SQL injection vulnerability in the huija bicycleSharingServer project up to commit 7b8a3ba48ad618604abd4797d2e7cf3b5ac7625a. The flaw resides in the searchAdminMessageShow function within AdminController.java. Attackers can manipulate the Title argument to inject arbitrary SQL statements against the backing database. The vulnerability is remotely exploitable and requires low-level privileges to trigger. The project does not use formal versioning, so no fixed or affected release numbers are published. A public exploit disclosure exists, increasing opportunistic risk against exposed instances.

Critical Impact
Authenticated remote attackers can inject SQL through the Title parameter of the admin message search endpoint, potentially exposing or altering stored data.

Affected Products

huija bicycleSharingServer up to commit 7b8a3ba48ad618604abd4797d2e7cf3b5ac7625a
Component: AdminController.java
Function: searchAdminMessageShow

Discovery Timeline

2025-06-27 - CVE-2025-6749 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-6749

Vulnerability Analysis

The vulnerability is a SQL injection flaw [CWE-74] within the admin message search handler. The searchAdminMessageShow method in AdminController.java accepts a Title request parameter and incorporates it into a database query without sufficient sanitization or parameterization. An authenticated attacker with low privileges can submit crafted input to alter query logic, read unauthorized rows, or modify stored data. The attack is launched over the network and does not require user interaction. Because the project does not use formal versioning, administrators cannot identify a fixed release by version string and must track the Git commit history directly.

Root Cause

The root cause is improper neutralization of special elements used in a SQL statement. The Title input flows into a query construction path, likely through string concatenation or unsafe templating, instead of a parameterized statement or an Object-Relational Mapping (ORM) binding. This allows SQL metacharacters supplied by the attacker to break out of the intended string literal context.

Attack Vector

An attacker authenticates to the application with a low-privilege account that can reach the admin message search endpoint. The attacker then submits a crafted Title value containing SQL syntax. The server concatenates the input into a query and the database executes the injected clauses. The exploit has been publicly disclosed through VulDB and the associated GitHub issue tracker, so defenders should assume automated probing is possible.

For technical reproduction details, see the GitHub Issue #6 Discussion and VulDB entry #314047.

Detection Methods for CVE-2025-6749

Indicators of Compromise

HTTP requests to admin message search endpoints containing SQL metacharacters such as single quotes, UNION SELECT, --, /*, or OR 1=1 in the Title parameter.
Unexpected database errors or stack traces originating from AdminController.searchAdminMessageShow in application logs.
Anomalous outbound data volumes from the application server tied to admin session identifiers.

Detection Strategies

Deploy Web Application Firewall (WAF) rules that inspect the Title parameter for SQL injection payload patterns.
Enable database query logging and alert on queries from the application role that reference system tables or use stacked statements.
Correlate authentication events with admin message searches to detect low-privilege accounts enumerating data beyond their normal scope.

Monitoring Recommendations

Monitor application and database logs for syntax errors tied to the searchAdminMessageShow handler.
Baseline normal admin search request volumes and alert on sudden spikes or repeated failed queries from a single session.
Track egress traffic from the application tier for anomalous payload sizes that could indicate bulk data extraction.

How to Mitigate CVE-2025-6749

Immediate Actions Required

Restrict network access to the admin interface to trusted management networks or VPN users only.
Audit all accounts with access to admin message search functionality and remove unused low-privilege accounts.
Deploy WAF signatures that block SQL injection patterns on the Title parameter.
Rotate database credentials if any suspicious queries have been observed in historical logs.

Patch Information

No official patch or versioned release is available at the time of writing. The project does not use versioning, so remediation requires forking the repository, applying parameterized queries to the searchAdminMessageShow method, and rebuilding from source. Track the huija/bicycleSharingServer repository for upstream fixes.

Workarounds

Replace string concatenation in AdminController.java with PreparedStatement bindings or JPA parameterized queries for the Title input.
Apply input allow-listing to constrain Title to expected character classes before query construction.
Enforce least-privilege database roles so the application account cannot read sensitive tables or execute data definition language (DDL) statements.
Disable the admin message search endpoint until a patched build is deployed if business processes allow.

bash

# Example nginx location block to restrict admin endpoints to a management CIDR
location /admin/searchAdminMessageShow {
    allow 10.10.0.0/24;
    deny all;
    proxy_pass http://bicycle_backend;
}