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.

The correct answer is D. Signature Recognition.

The monitoring system is detecting traffic because it matches known attack patterns stored in a threat database. When the payload sequence is slightly changed, the alert no longer triggers. This is the classic behavior of signature-based detection.

CEH-aligned IDS material explains that signature recognition means that, for every known hacker technique, engineers code a detection pattern into the system. It describes this as simple pattern matching, such as examining packets for a known malicious pattern .

Option A. Protocol Anomaly Detection is incorrect because protocol anomaly detection identifies deviations from expected protocol behavior, not just known exploit strings.

Option B. Anomaly Detection is incorrect because anomaly detection compares behavior against a baseline of normal activity. The scenario describes matching known attack payloads.

Option C. Stateful Protocol Analysis is incorrect because stateful protocol analysis evaluates protocol state and expected protocol behavior across sessions.

Option D. Signature Recognition is correct because detection depends on matching known patterns, and small changes to the exploit sequence can evade detection.

Therefore, the best answer is D. Signature Recognition.

This scenario demonstrates a classic case of Session Fixation, a session hijacking technique explicitly covered under the CEH v13 Web Application Hacking module. Session fixation occurs when an attacker sets or predicts a valid session identifier and forces a victim to authenticate using that same session ID.

In the given question, two critical vulnerabilities are highlighted:

The session ID is embedded in the URL

The application does not regenerate the session ID after login

According to CEH v13, secure applications must regenerate session identifiers after successful authentication to prevent fixation attacks. If this does not occur, an attacker can craft a URL containing a known session ID and trick the victim into clicking it. Once the victim logs in, the attacker reuses the same session ID to gain unauthorized access.

CEH documentation states that session fixation is particularly effective when:

Session IDs are passed via URL parameters

Sessions persist across authentication

Secure cookie attributes are not enforced

Other options are incorrect because:

XSS-based cookie theft requires client-side script injection.

DNS cache poisoning is unrelated to session management.

CSRF exploits user trust but does not directly hijack sessions.

Thus, Session Fixation by pre-setting the token in a URL is the most effective attack in this case.

According to the CEH Network and Perimeter Security module, one of the most effective and widely used firewall evasion techniques is the use of encrypted communication channels. When traffic is encrypted using protocols such as HTTPS, TLS, or VPN tunnels, traditional firewalls and packet-inspection tools may be unable to inspect payload contents unless SSL/TLS inspection is explicitly enabled.

CEH documentation explains that attackers commonly encrypt command-and-control (C2) traffic to:

Blend in with legitimate encrypted traffic

Bypass content-based inspection

Evade signature-based detection

Option B is therefore correct.

Option A (IP spoofing) is less effective against stateful firewalls.

Option C is a human-focused attack, not firewall evasion.

Option D has no relevance to firewall bypass techniques.

CEH highlights encryption misuse as a major blind spot in perimeter defenses.

The correct answer is D. UNION SQL Injection because the key observation is that the application’s response shows data from another table merged into the same page results, meaning the injected payload successfully combined two result sets into a single output. In CEH-aligned SQL injection taxonomy, UNION-based SQL injection occurs when an attacker uses the SQL UNION (or UNION ALL) operator to append the results of a second SELECT query to the original query’s results. If the application prints query results to the page, UNION injection is especially powerful because it can directly exfiltrate database contents in-band through the normal web response.

The scenario describes input into a numeric parameter in the customer dashboard (commonly an id value in a query such as selecting loan details). By manipulating this parameter, the attacker causes the back-end query to return not only the intended loan record(s) but also employee information from a different table. That is the hallmark of UNION SQL injection: retrieving unrelated columns/rows by crafting a second SELECT that matches the original query’s column count and compatible data types, then unioning it with the legitimate query so both datasets render together. Attackers often enumerate the number of columns (e.g., with ORDER BY tests) and then identify which columns are reflected in the response to place sensitive data where it will be displayed.

Why the other options do not match: Error-based SQL injection relies on database error messages to leak information, rather than cleanly merging results into the page. Blind SQL injection yields no direct data in the response and instead infers information via boolean conditions or time delays. Second-order SQL injection happens when malicious input is stored first and executed later in a different context; the prompt describes immediate, in-response merging of data.

Therefore, the behavior most directly indicates UNION SQL injection.

The central failure in the scenario is that a lost smartphone remained capable of accessing sensitive data, which means the organization lacked an effective lost device response control. In CEH-aligned mobile security guidance, one of the most important protections for lost or stolen devices is the ability to remotely secure the endpoint by locking it and wiping corporate data. This is typically implemented through Mobile Device Management tools and enterprise mobility controls. Registering devices with a remote locate and wipe facility ensures the security team can immediately take action once a device is reported missing, reducing the window in which an attacker can use stored sessions, cached credentials, saved tokens, or application access to reach protected resources such as patient records.

Option C is the best answer because it addresses both key needs implied by the incident: location capability to aid recovery and remote wipe to eliminate data exposure if recovery is uncertain. In healthcare environments, where protected health information is highly sensitive, CEH documentation emphasizes compensating controls that protect confidentiality when physical control of the device is lost. Remote wipe supports incident containment by preventing further access and limiting data disclosure.

Option B only provides tracking and does not guarantee data protection if the device cannot be recovered quickly. Option A helps protect data in transit on untrusted networks, but it does not solve the risk of a stolen device already authenticated to internal systems. Option D can help overall hygiene, but antivirus and DLP do not reliably stop misuse of a legitimately authenticated, lost device. Remote locate and wipe is the most direct mitigation for this exact gap.

This scenario represents a Tautology-Based SQL Injection, a fundamental SQL injection technique covered under the Web Application Hacking module in the CEH v13 curriculum. The defining characteristic of this attack is the injection of a condition that always evaluates to TRUE, thereby bypassing authentication or authorization controls.

In the given example, the injected input 1 OR ' T ' = ' T ' ; -- manipulates the logical condition of the SQL query. A typical vulnerable login query may resemble:

SELECT * FROM users WHERE user_id = 1 AND password = ' input ' ;

When the attacker submits the injected payload, the resulting SQL statement becomes:

SELECT * FROM users WHERE user_id = 1 OR ' T ' = ' T ' ; -- ' ;

The expression ' T ' = ' T ' is a tautology, meaning it always evaluates to TRUE regardless of context. As a result, the database returns records without properly validating the user’s credentials, granting unauthorized access.

According to EC-Council CEH v13, tautology-based SQL injection is classified as a Boolean-based injection technique where attackers exploit improper input validation to alter the logical flow of SQL queries. This attack does not depend on database error messages (as in Error-Based SQL Injection), does not extract data using UNION statements (Union-Based SQL Injection), and does not rely on response delays (Time-Based Blind SQL Injection).

CEH v13 emphasizes that such attacks are especially effective against login forms and authentication mechanisms when developers fail to implement input sanitization, parameterized queries, or prepared statements. This attack is one of the most common and exam-tested SQL injection types because it clearly demonstrates how flawed logic can compromise application security without advanced techniques.

Understanding tautology-based SQL injection is critical for ethical hackers, as it forms the foundation for identifying and mitigating more complex SQL injection variants.