CVE-2026-71237 in IoT-PHP
Summary
by MITRE • 08/05/2026
Miantang/IoT-PHP's index.php implements a POST /userlogin route that reads the password directly from $_POST['pwd'] with no sanitization and concatenates it into a raw SQL string: mysql_query("select * from userlists where username='$username' and password='$password' limit 1"). The username value is passed through htmlspecialchars(), which does not encode single quotes by default and therefore does not prevent SQL injection through the password field. An unauthenticated attacker can submit a payload such as pwd=' OR '1'='1 to bypass authentication and, via UNION-based injection, extract arbitrary data from the database.
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Analysis
by VulDB Data Team • 08/05/2026
This vulnerability represents a critical sql injection flaw in the Miantang/IoT-PHP application's user authentication mechanism. The implementation demonstrates poor input validation practices where the password parameter is directly incorporated into a mysql_query string without any sanitization or escaping mechanisms. The system processes the username through htmlspecialchars() which, while effective for preventing cross-site scripting attacks, fails to address sql injection threats since it does not encode single quotes that are fundamental to sql injection techniques. This creates an exploitable condition where attackers can manipulate the sql query structure by injecting malicious payloads into the password field.
The technical exploitation occurs through standard sql injection vectors where an attacker submits a crafted payload such as pwd=' OR '1'='1 which modifies the intended sql query from its original structure of "select from userlists where username='$username' and password='$password' limit 1" to something like "select from userlists where username='$username' and password='' OR '1'='1' limit 1". This modification causes the database to return all records matching the username condition or simply true, effectively bypassing authentication entirely. The vulnerability is particularly dangerous because it operates without requiring authentication credentials, making it an unauthenticated attack vector that can be exploited by anyone with access to the application's interface.
The operational impact of this vulnerability extends beyond simple authentication bypass to include potential data exfiltration through union-based sql injection techniques. An attacker with successful exploitation can extract arbitrary database content including user credentials, personal information, and potentially sensitive system data. This represents a severe compromise of confidentiality and integrity as the vulnerability allows unauthorized access to the entire user database. The attack surface is particularly concerning given that this affects a core authentication mechanism where successful exploitation directly leads to full system compromise.
Mitigation strategies must address both immediate remediation and long-term architectural improvements to prevent similar vulnerabilities. The most critical immediate fix involves implementing proper sql query parameterization using prepared statements with bound parameters instead of direct string concatenation. This approach completely eliminates the risk of sql injection by separating sql code from data inputs, making it compliant with cwe-89 standard for sql injection prevention. Additionally, implementing input validation and sanitization specifically for sql characters, employing least privilege database access controls, and deploying web application firewalls can provide defense-in-depth measures. The solution should align with mitre att&ck framework's tactic of credential access and privilege escalation by ensuring that authentication mechanisms cannot be trivially bypassed through code injection vulnerabilities.