CVE-2025-13276: Online-Banking-System SQL Injection Flaw

CVE-2025-13276 Overview

CVE-2025-13276 is a SQL injection vulnerability in the g33kyrash Online-Banking-System application. The flaw resides in /index.php, where the Username parameter is passed unsanitized into a SQL query. An unauthenticated remote attacker can manipulate the input to alter query logic, read database contents, or modify stored records. The project follows a rolling release model, and affected code is tracked up to commit 12dbfa690e5af649fb72d2e5d3674e88d6743455. Public exploit details have been published, increasing the likelihood of opportunistic abuse against exposed deployments. The weakness is classified under [CWE-74] (Improper Neutralization of Special Elements in Output Used by a Downstream Component).

Critical Impact

Unauthenticated attackers can inject SQL through the login Username field of an online banking application, exposing credentials and account data.

Affected Products

• g33kyrash Online-Banking-System (rolling release)
• Builds up to commit 12dbfa690e5af649fb72d2e5d3674e88d6743455
• Deployments exposing /index.php to untrusted networks

Discovery Timeline

• 2025-11-17 - CVE-2025-13276 published to NVD
• 2026-04-29 - Last updated in NVD database

Technical Details for CVE-2025-13276

Vulnerability Analysis

The vulnerability exists in the authentication handler within /index.php. The application accepts the Username POST parameter and concatenates it directly into a SQL query without parameterization or escaping. Attackers submit crafted input containing SQL metacharacters to break out of the intended string context and append arbitrary clauses. This grants control over the WHERE predicate of the login query and any downstream statements that reuse the value.

Because the affected endpoint is the unauthenticated login form, exploitation requires no credentials and no user interaction. The exploit is publicly available, and the project's rolling release model means no fixed version identifier is published.

Root Cause

The root cause is improper neutralization of user-supplied input before inclusion in a SQL statement. The code path constructs queries through string concatenation rather than prepared statements with bound parameters. Input validation routines do not enforce a character allowlist or reject SQL syntax tokens for the Username field.

Attack Vector

An attacker sends an HTTP POST request to /index.php with a malicious Username value. Typical payloads use boolean-based or UNION-based techniques to bypass authentication or exfiltrate data from the underlying database. The attack is remote, network-reachable, and requires no privileges. The public proof-of-concept is hosted in the GitHub SQL Injection Report and tracked in VulDB #332611.

No verified code examples are available for this advisory. Refer to the linked report for the documented payload structure.

Detection Methods for CVE-2025-13276

Indicators of Compromise

• POST requests to /index.php containing SQL metacharacters such as ', --, OR 1=1, or UNION SELECT in the Username field
• Unexpected successful logins without a corresponding valid credential record in application logs
• Database error messages returned in HTTP responses referencing syntax errors near user-controlled tokens
• Sudden spikes in failed login attempts followed by anomalous session creation

Detection Strategies

• Deploy web application firewall (WAF) rules that inspect POST bodies for SQL syntax in authentication parameters
• Enable database query logging and alert on queries containing tautologies or stacked statements originating from the web application user
• Correlate web server access logs with database audit logs to identify malformed login attempts that reach the SQL layer

Monitoring Recommendations

• Monitor /index.php for elevated request rates and abnormal payload sizes on the Username field
• Track database read volumes from the banking application service account and alert on deviations from baseline
• Forward web, application, and database telemetry to a centralized analytics platform for cross-source correlation

How to Mitigate CVE-2025-13276

Immediate Actions Required

• Restrict network access to the affected application to trusted networks until remediation is complete
• Deploy WAF signatures that block SQL injection patterns targeting the Username parameter on /index.php
• Rotate database credentials and any cached session tokens if exploitation is suspected
• Review database audit logs for queries indicative of injection attempts since deployment

Patch Information

The project uses a rolling release model, so no versioned patch identifier is available. Operators should pull the latest commit from the upstream repository and verify that the login handler uses parameterized queries before redeploying. Track advisory updates through VulDB CTI ID #332611 and the VulDB Submission ID #690087.

Workarounds

• Replace string-concatenated SQL with prepared statements using bound parameters for the Username and Password fields
• Apply server-side input validation that rejects characters outside the expected username character set
• Run the database account used by the application with least-privilege permissions to limit the impact of successful injection
• Place the application behind a reverse proxy with strict request filtering until upstream code is corrected

# Example WAF rule (ModSecurity) blocking SQLi patterns on the login endpoint
SecRule REQUEST_URI "@streq /index.php" \
  "chain,phase:2,deny,status:403,id:1013276,msg:'Possible SQLi on Username'"
  SecRule ARGS:Username "@rx (?i)(\bunion\b.*\bselect\b|--|;|\bor\b\s+1=1|')" "t:none"