ECCouncil 312-50v13 (Certified Ethical Hacker v13) Practice Test 23

Question 220

A production hardening ticket was raised after this confirmed observation: An invoice-import API allows DTD declarations in third-party XML, and its parser follows an attacker-defined external reference to a sensitive local resource. Which action best targets the risk?

  1. Validate content and store uploads outside executable web paths
  2. Authorize every object access against the authenticated principal
  3. Enforce outbound destination allowlists and block internal metadata ranges
  4. Disable DTD and external entity resolution for untrusted XML
  5. Sanitize allowed rich content and use output encoding on display
  6. Avoid shell invocation and pass validated arguments to direct process APIs

Explanation

Correct Answer

D:

Secure parser settings stop attacker-supplied XML from loading external resources while preserving ordinary document parsing. The underlying condition is that XXE occurs when XML parsing resolves untrusted external entities or DTD resources, potentially reaching files or internal URLs from the server.

Incorrect Answers

A:

Re-encoding images, controlled file types, and nonexecutable storage prevent uploaded content from becoming server-executed code; it would improve unsafe file upload, not directly correct the reported XML external entity processing issue.

B:

Server-side object ownership or policy checks stop horizontal data access even when identifiers are guessable or sequential; the measure addresses a different trust boundary from the XML external entity processing finding.

C:

URL and IP validation plus restricted egress prevent the server from acting as a proxy to sensitive services outside the feature's intended scope; the required correction concerns XML external entity processing, so this is not the targeted control.

E:

Validation and rendering safeguards stop saved comments from becoming active scripts when retrieved by other users; the exposure here is XML external entity processing, which calls for another protective mechanism.

F:

Separating executable selection from user data prevents shell parsing from transforming input into additional commands; the action is aimed at operating-system command injection; it leaves the central XML external entity processing condition unresolved.

Question 221

As part of a sanctioned audit, a reviewer observes: A tester captures a WPA2 four-way handshake and can verify guessed network passwords offline without repeatedly contacting the access point. Which behavior is illustrated?

  1. KRACK handshake implementation
  2. WPA3-SAE authentication
  3. WPA2-Personal weak passphrase
  4. WPS PIN weakness

Explanation

Correct Answer

C:

WPA2-Personal derives key material from a shared passphrase, so weak secrets can be tested against a captured handshake outside the network. For a production safeguard, operators can use a strong random passphrase or move to enterprise authentication; high-entropy secrets resist offline guesses, while per-user enterprise credentials remove the single shared passphrase from the whole fleet.

Incorrect Answers

A:

Key reinstallation attacks exploit certain four-way-handshake implementation flaws, not the mere existence of a strong WPA2 passphrase; those effects are not the WPA2-Personal weak passphrase pattern evidenced by the assessment.

B:

WPA3-Personal uses SAE rather than the WPA2-Personal PSK handshake, improving resistance to passive offline password guessing under proper implementation; the case demonstrates WPA2-Personal weak passphrase rather than the alternate mechanism.

D:

Some WPS PIN implementations expose an effectively split PIN validation process and weak rate controls, making this enrollment method attackable; the test record points specifically to WPA2-Personal weak passphrase, not this separate mechanism.

Question 222

A follow-up review must reduce the risk revealed here: An anomaly detector reports flagless TCP packets traversing a branch firewall, and analysts need to corroborate whether the hosts' inconsistent reactions are exploitable services. Which defensive measure fits the specific failure mode?

  1. Validate ambiguous UDP results with protocol-aware requests
  2. Normalize suspicious flag patterns and corroborate scanner output
  3. Reduce authorized probe rates and correlate results with perimeter logs
  4. Review supported TLS versions and certificate validation on the real service

Explanation

Correct Answer

B:

Firewall or IDS normalization catches anomalous traffic while standard connection tests separate fingerprint quirks from real exposure. It targets the actual failure mode: NULL scanning sends a zero-flag TCP segment and infers states from implementation-dependent responses; it is not a universally reliable port test.

Incorrect Answers

A:

Application-specific probes and correlated firewall logs help distinguish a silent UDP listener from network filtering without guessing from silence; the specific root cause belongs to TCP NULL scan, beyond this control's intended scope.

C:

Controlled timing improves reproducibility and avoids mistaking defensive drops or transient congestion for a change in service configuration; it would improve rate-limited scan results, not directly correct the reported TCP NULL scan issue.

D:

Hardening protocol negotiation and certificate chains prevents downgrade and impersonation weaknesses that a simple open-port scan cannot detect; the measure addresses a different trust boundary from the TCP NULL scan finding.

Question 223

The assessor confirmed this exposure: An incident leaves few executable files, but process telemetry reveals encoded scripts creating in-memory network connections through a legitimate interpreter. Which change most directly closes the underlying security gap?

  1. Inspect anomalous periodic egress and block unapproved destinations
  2. Combine static indicators with isolated dynamic observation
  3. Collect process command lines and script telemetry with behavioral detection
  4. Keep isolated immutable backups and restrict bulk file-write privileges

Explanation

Correct Answer

C:

Observing interpreter behavior and memory-backed execution identifies activity that signature scans of executable files may overlook. The technical basis for the recommendation is that fileless malware favors memory and legitimate interpreters or system tools rather than installing a traditional standalone binary on disk.

Incorrect Answers

A:

Network telemetry and destination reputation can reveal remote-control channels even when the payload hides its instructions inside ordinary-looking requests; its security benefit applies principally to command-and-control beacon, not the defect described; the tested fault instead involves fileless memory execution.

B:

A controlled sandbox can expose unpacked behavior and runtime imports while avoiding conclusions based only on unusual file entropy; the exposure here is fileless memory execution, which calls for another protective mechanism.

D:

Recoverable backup copies and limited write access reduce operational leverage even if an endpoint successfully encrypts its reachable files; this is relevant to a separate ransomware encryption activity scenario, rather than the identified exposure; the tested fault instead involves fileless memory execution.

Question 224

The tester submits the following verified finding: An endpoint tool alerts when a document reader spawns a scripting host that contacts an unknown network service. Which technique or condition is involved?

  1. Spyware collection
  2. Sandbox detonation
  3. File-infecting virus
  4. Fileless memory execution
  5. Behavioral EDR alert
  6. Packed executable analysis

Explanation

Correct Answer

E:

Behavioral detection evaluates execution relationships and suspicious actions rather than requiring an exact previously known malware file signature. This is why teams should investigate process ancestry and enforce endpoint response policy; parent-child telemetry reveals unusual execution chains and supports containment of suspicious behavior across multiple different payload hashes.

Incorrect Answers

A:

Spyware covertly collects user or system information and transmits it for monitoring or abuse; it does not need to encrypt or destroy files; the test record points specifically to behavioral EDR alert, not this separate mechanism.

B:

Dynamic malware analysis studies execution effects under controlled conditions; evasion and missing environmental triggers can produce incomplete results; that behavior is distinct from the behavioral EDR alert finding being classified.

C:

A virus attaches itself to another file or executable and commonly depends on host execution to spread, unlike a self-propagating worm; the scenario identifies behavioral EDR alert, which has a different triggering condition.

D:

Fileless malware favors memory and legitimate interpreters or system tools rather than installing a traditional standalone binary on disk; the defining symptom in the prompt is associated with behavioral EDR alert instead.

F:

Executable packers transform or encapsulate code and reveal it during execution; packing can serve legitimate distribution or malware evasion; the reported conditions are characteristic of behavioral EDR alert, not that path.

Question 225

During a documented lab review, an analyst notes: An advanced search query locates a directory of publicly indexed backup files restricted only by obscurity of their path. What mechanism should be recorded?

  1. Technology banner aggregation
  2. Search operators for exposure
  3. Email header analysis
  4. Search engine indexing

Explanation

Correct Answer

B:

Search operators refine the results a search engine has already indexed; they do not bypass origin authentication to retrieve private content. The control that addresses this failure path is to require authorization on backup locations and block unintended indexing; an index exclusion alone is not an access control; storage permissions and web server rules must prevent unauthenticated download.

Incorrect Answers

A:

Internet device search engines index observable service responses and metadata collected through their own scans; an assessor can review those records passively; that behavior is distinct from the search operators for exposure finding being classified.

C:

Email headers record mail transfer hops and authentication signals; display names alone are untrusted and do not prove the actual origin; the defining symptom in the prompt is associated with search operators for exposure instead.

D:

Search-engine caches and indexes can retain discoverable content even after an origin page changes; removing a live link alone does not ensure deindexing; the events given do not establish this behavior but do support search operators for exposure.

Question 226

A follow-up review must reduce the risk revealed here: A vulnerability finding relies on a single unusual HTTP error with no reproduced unauthorized effect, and management requests proof before applying a disruptive emergency change. Which defensive measure fits the specific failure mode?

  1. Provide tightly scoped scanner credentials and rotate them after use
  2. Correlate external results with internal authenticated assessments
  3. Use a minimal authorized reproduction and collect corroborating logs
  4. Verify the affected asset and original attack condition after the change

Explanation

Correct Answer

C:

Controlled evidence establishes the vulnerable path and limits false claims while keeping the proof within approved testing boundaries. That correction is linked to the fact that vulnerability validation separates heuristic indicators from evidence of the claimed security impact; a response anomaly alone can be caused by ordinary application errors.

Incorrect Answers

A:

A controlled identity improves coverage while limiting the impact if stored assessment credentials are leaked or misused; this is relevant to a separate authenticated vulnerability scan scenario, rather than the identified exposure; the tested fault instead involves vulnerability validation.

B:

Multiple vantage points reveal exposures that an internet-facing scanner cannot see, preventing unsupported conclusions from a clean outside report; the tested weakness is vulnerability validation, not the false-negative scan configuration addressed here.

D:

A targeted retest confirms both patch applicability and the closure of the particular finding instead of accepting ticket state as technical proof; the proposed improvement would make sense for remediation retest but not as the main fix here; the tested fault instead involves vulnerability validation.

Question 227

The testing team seeks a specific preventive recommendation for this finding: A mobile payments app exposes an internal transaction activity to other Android packages and does not verify caller permissions before processing its intent data. What should be implemented?

  1. Review requested permissions and block unnecessary sensitive grants
  2. Enforce HTTPS and prohibit cleartext network policies in app configuration
  3. Minimize exported components and enforce permissions for sensitive entry points
  4. Enforce managed app sources and mobile threat defense

Explanation

Correct Answer

C:

Explicit component exposure and caller checks prevent another application from invoking privileged behavior meant only for internal flows. This matters for the observed attack path because exported Android components are accessible across app boundaries subject to permissions; missing checks can turn internal functionality into an external attack surface.

Incorrect Answers

A:

Feature-based permission review limits unintended data collection and reduces blast radius when an app misbehaves; that change targets excessive mobile permissions, while the confirmed weakness involves Android exported component.

B:

TLS protects API exchanges in transit and platform policy stops accidental fallback to unencrypted endpoints; it would improve cleartext mobile API traffic, not directly correct the reported Android exported component issue.

D:

Trusted distribution, signature checks, and endpoint policy reduce installation of repackaged applications from uncontrolled sites; the required correction concerns Android exported component, so this is not the targeted control.

Question 228

A remediation meeting focuses on the following finding: An unsolicited phone caller impersonates company IT and demands a time-limited verification token, asserting that the user's account will close without immediate cooperation. Which proposed action best addresses its root cause?

  1. Train staff to end unsolicited calls and call back through official support numbers
  2. Use controlled visitor escort and anti-tailgating procedures
  3. Disable unapproved removable media and offer safe found-device reporting
  4. Use number matching and phishing-resistant authentication with prompt anomaly alerts

Explanation

Correct Answer

A:

Independent dial-back prevents a caller's claimed identity and spoofable phone number from authorizing sensitive account actions. It targets the actual failure mode: vishing uses voice calls to deceive a person into disclosing secrets or performing unsafe actions, often relying on caller-ID spoofing and urgency.

Incorrect Answers

B:

Individual access checks and visitor handling prevent one person's authorized badge from implicitly admitting an unverified companion; the action is aimed at tailgating; it leaves the central vishing condition unresolved.

C:

Device controls block execution or access from unknown media while a reporting route avoids relying only on curiosity-resistant behavior; this is relevant to a separate USB baiting scenario, rather than the identified exposure; the tested fault instead involves vishing.

D:

Challenge context and stronger factors reduce blind approvals, while alerting and throttling expose the repetitive abuse pattern; the tested weakness is vishing, not the MFA push fatigue configuration addressed here.

Question 229

The tester submits the following verified finding: A tester discovers that a production payment endpoint was not listed among the authorized target addresses. The client asks the team to continue immediately. Which technique or condition is involved?

  1. Incident stop condition
  2. Written rules of engagement
  3. Threat modeling
  4. Passive reconnaissance

Explanation

Correct Answer

B:

The signed rules of engagement define permitted assets, methods, windows, contacts, and stop conditions. Informal requests cannot safely supersede that documented authorization boundary. A practical defensive response is to obtain a signed scope amendment before touching the payment endpoint; a documented scope change protects the client and tester, aligns approval with the new asset, and avoids treating a verbal request as blanket consent.

Incorrect Answers

A:

Stop conditions are engagement safety triggers that require pausing potentially harmful activity and notifying designated stakeholders even if the planned test window remains open; the reported conditions are characteristic of written rules of engagement, not that path.

C:

Threat modeling is a structured way to reason about assets, entry points, trust boundaries, and attack paths before or during implementation; this would classify another type of evidence, whereas the actual finding shows written rules of engagement.

D:

Passive reconnaissance derives intelligence from existing third-party or public sources rather than probing the target systems directly; it can reveal assets without generating target-side scan traffic; the relevant mechanism in the observed workflow is written rules of engagement instead.

Question 230

The testing team seeks a specific preventive recommendation for this finding: A Linux host advertises RPC services to workstation networks that have no operational need to reach the portmapper or its dynamic endpoints. What should be implemented?

  1. Use SNMPv3 with authentication, privacy, and management ACLs
  2. Restrict share listing and access through SMB permissions and segmentation
  3. Disable anonymous enumeration and review guest or null-session policies
  4. Restrict rpcbind access to networks that need RPC services

Explanation

Correct Answer

D:

Management network controls suppress unnecessary program enumeration and narrow exposure of related RPC daemons. The underlying condition is that rpcbind maps ONC RPC program identifiers to network addresses or ports, providing service discovery without directly enumerating file content.

Incorrect Answers

A:

SNMPv3 protects management exchanges, while device and network restrictions reduce exposure of sensitive interface and configuration details; the required correction concerns rpcbind service inventory, so this is not the targeted control.

B:

Share and NTFS permissions plus network isolation reduce unauthorized resource browsing even when SMB must remain available to staff; its security benefit applies principally to SMB share enumeration, not the defect described; the tested fault instead involves rpcbind service inventory.

C:

Explicitly limiting unauthenticated SMB and RPC access prevents account and share disclosure while preserving required authenticated service use; the exposure here is rpcbind service inventory, which calls for another protective mechanism.

Certified Ethical Hacker v13 (312-50v13) Practice Tests