312-50v13 Exam Dumps : Certified Ethical Hacker Exam (CEHv13)

This question describes a classic example of Tautology-Based SQL Injection, a subcategory of SQL Injection attacks which fall under Web Application Hacking in the CEH curriculum.

In a tautology-based SQL injection, the attacker injects a SQL fragment that always evaluates to true, thus bypassing the authentication mechanism. The string ' C ' ll-T; — is a malformed variant, possibly meant to represent ' OR ' 1 ' = ' 1 ' ; --, which is one of the most basic and widely recognized tautology-based injection payloads. When injected into a vulnerable SQL query, this kind of input manipulates the WHERE clause of the query so that it always evaluates to true, regardless of the original conditions.

Here’s how it works:

If the SQL query is:

SELECT * FROM users WHERE username = ' $username ' AND password = ' $password ' ;

And the attacker inputs:

' OR ' 1 ' = ' 1 ' ; --

The query becomes:

SELECT * FROM users WHERE username = ' ' OR ' 1 ' = ' 1 ' ; -- ' AND password = ' ' ;

This results in the execution of:

SELECT * FROM users WHERE ' 1 ' = ' 1 ' ;

Which always evaluates to true, thereby bypassing authentication and allowing unauthorized access.

This method does not rely on error messages (Error-Based), timing delays (Time-Based Blind), or UNION statements (Union-Based). Its goal is to exploit logic within the query structure itself using boolean-based manipulation.

According to EC-Council ' s CEH v13 Module: Web Application Hacking, understanding tautology-based injection is critical because it ' s one of the most common ways attackers bypass login forms on poorly secured web applications.

CEH v13 emphasizes that after identifying vulnerabilities during scanning, testers must validate findings to determine real impact and eliminate false positives. This requires safe, controlled exploitation using approved tools such as Metasploit, Nikto, or custom proof-of-concept scripts. Misconfigurations labeled as medium-risk may still provide privilege escalation, data exposure, or footholds for further attacks. CEH methodology reinforces that exploitation should always follow the scope and rules of engagement and should avoid disruptive activities like brute-forcing or DoS attacks unless explicitly authorized. Ignoring the vulnerabilities is never acceptable in a professional assessment. Verifying the issue helps the organization prioritize remediation using evidence-based results. Therefore, the correct next step is to verify the vulnerability through controlled exploitation.

Ping of Death is a classic Denial-of-Service technique in which an attacker sends oversized or malformed IP packets that exceed the maximum allowed size when reassembled. In IP networks, the maximum packet size is 65,535 bytes. Historically, attackers exploited fragmentation by sending a series of IP fragments that, when reassembled by the target, resulted in a packet larger than the permitted limit or produced an invalid buffer condition. Vulnerable systems could crash, reboot, or become unstable because the network stack mishandled the reassembly process or failed to properly validate packet length and structure.

The scenario matches this behavior precisely: Sofia transmits “oversized, malformed packets” and the server “crashes intermittently due to processing failures.” That symptom is more consistent with a malformed-packet handling flaw than with pure traffic volume. An ICMP flood and an ACK flood are volumetric or resource-exhaustion attacks that overwhelm bandwidth or connection-handling capacity, typically degrading performance rather than directly causing crashes from malformed packet parsing. A Smurf attack is an amplification-based ICMP attack using broadcast addresses to multiply traffic toward a victim; again, it is about volume, not crafted malformed packets that trigger parsing failures.

CEH guidance highlights that PoD-style attacks exploit improper packet validation and reassembly logic. Modern systems are generally patched, but poorly maintained devices, legacy OS stacks, and some embedded implementations can still exhibit instability when exposed to malformed fragmentation and reassembly edge cases.