CVE-2018-25362: Twitter-Clone SQL Injection Vulnerability

CVE-2018-25362 Overview

CVE-2018-25362 is a SQL injection vulnerability in Twitter-Clone version 1, an open-source PHP application hosted on GitHub. The flaw resides in follow.php, where the userid parameter is concatenated into a SQL query without sanitization or parameterization. Attackers can submit union-based or time-based blind SQL injection payloads to extract sensitive database content. Exploitable data includes usernames, password hashes, and underlying database credentials. The issue is classified under CWE-89: Improper Neutralization of Special Elements used in an SQL Command.

Critical Impact
Unauthenticated network attackers can extract full database contents, including credentials, by injecting SQL through the userid parameter in follow.php.

Affected Products

Twitter-Clone version 1 (PHP application)
The vulnerable component is follow.php
Distribution: PHP-Twitter-Clone GitHub repository

Discovery Timeline

2026-05-25 - CVE-2018-25362 published to the National Vulnerability Database
2026-05-26 - CVE-2018-25362 last updated in NVD

Technical Details for CVE-2018-25362

Vulnerability Analysis

The vulnerability is a classic SQL injection in the follow.php endpoint of Twitter-Clone 1. The application accepts a userid parameter from the client and embeds it directly into a SQL statement executed against the backend database. No input validation, type casting, escaping, or prepared statements are applied. As a result, an attacker can break out of the intended query context and append arbitrary SQL.

Both union-based and time-based blind SQL injection techniques are viable. Union-based attacks return data inline in the application response, while time-based blind attacks use functions such as SLEEP() to infer query results from response latency. The application requires no authentication to reach the vulnerable code path, expanding the pool of potential attackers to any network-reachable client.

Root Cause

The root cause is the absence of parameterized queries in the database interaction layer. The userid parameter flows from the HTTP request directly into a string-concatenated SQL query. The codebase predates the security improvements introduced in modern PHP data access libraries and does not use PDO prepared statements or mysqli parameter binding.

Attack Vector

The attack vector is network-based and requires no privileges or user interaction. An attacker sends a crafted HTTP request to follow.php with a malicious userid value. Payloads typically include UNION SELECT statements to enumerate tables and exfiltrate columns such as username and password. Time-based payloads leveraging SLEEP() or BENCHMARK() enable extraction even when query results are not reflected in the HTTP response. A public proof of concept is documented at Exploit-DB #45230 and the VulnCheck Twitter Clone SQL Injection Advisory.

The vulnerability manifests when the userid parameter is appended to the SQL query string in follow.php. See the referenced advisories above for technical proof-of-concept details.

Detection Methods for CVE-2018-25362

Indicators of Compromise

HTTP requests to follow.php containing SQL keywords such as UNION, SELECT, SLEEP(, BENCHMARK(, or INFORMATION_SCHEMA in the userid parameter.
Web server access logs showing unusually long userid values or URL-encoded SQL syntax (%27, %20OR%20, %20UNION%20).
Spikes in database response times correlated with requests to follow.php, indicating time-based blind injection.
Unexpected outbound database queries against mysql.user, information_schema.tables, or other system catalogs.

Detection Strategies

Deploy a web application firewall ruleset that inspects query and body parameters for SQL injection signatures.
Enable database query logging and alert on queries containing UNION operators against authentication tables.
Correlate web access logs with database slow-query logs to identify time-based injection attempts.

Monitoring Recommendations

Monitor authentication tables for unauthorized read access patterns from the web application service account.
Track HTTP 500 responses from follow.php, which often indicate malformed injection attempts.
Alert on repeated requests to follow.php from a single source IP within a short window.

How to Mitigate CVE-2018-25362

Immediate Actions Required

Remove Twitter-Clone 1 from production exposure if it is not actively maintained. The project on GitHub does not have an official vendor patch.
Restrict network access to the application using firewall rules or reverse proxy access control lists.
Rotate any database credentials used by the application, as they may have been exposed.
Audit the underlying database for evidence of unauthorized SELECT activity against user tables.

Patch Information

No official vendor patch is available. The PHP-Twitter-Clone repository is not actively maintained. Mitigation requires source-level remediation by replacing string concatenation in follow.php with parameterized queries using PDO::prepare() or mysqli_stmt_bind_param(). Refer to the VulnCheck advisory for additional context.

Workarounds

Cast the userid parameter to an integer before passing it to the database query, for example $userid = (int)$_GET['userid'];.
Place the application behind a web application firewall with SQL injection signatures enabled.
Disable or remove the follow.php endpoint if the follow functionality is not required.
Apply database least-privilege principles so the application account cannot read administrative tables.

bash

# Configuration example: nginx rule to block obvious SQLi patterns on follow.php
location /follow.php {
    if ($args ~* "(union.*select|sleep\(|benchmark\(|information_schema)") {
        return 403;
    }
}