In the context of CompTIA PenTest+ and vulnerability analysis, the distinction between credentialed and non-credentialed scans is critical for determining the depth and perspective of a security assessment. A non-credentialed scan (often referred to as unauthenticated or 'black-box') simulates an e…In the context of CompTIA PenTest+ and vulnerability analysis, the distinction between credentialed and non-credentialed scans is critical for determining the depth and perspective of a security assessment. A non-credentialed scan (often referred to as unauthenticated or 'black-box') simulates an external attacker with no specific privileges or knowledge of the target system. The scanner queries the target over the network to identify open ports, protocols, and listening services. It relies on banner grabbing and network responses to infer potential vulnerabilities. While this provides a realistic view of what an outsider can see, it often results in higher false positives and cannot detect client-side vulnerabilities or missing local patches.
Conversely, a credentialed scan (authenticated or 'white-box') involves providing the scanner with valid user credentials (such as SSH, SMB, or SNMP logins) to authenticate against the target. This simulates an insider threat or an attacker who has already compromised an account. Because the scanner logs into the system, it can directly query the operating system’s kernel, registry, and file system. This allows for a granular audit of installed software, specific patch levels, configuration files, and permissions. Credentialed scans are far more accurate, producing fewer false positives and revealing vulnerabilities that are invisible from the network perimeter. For a comprehensive assessment, PenTest+ methodology typically recommends utilizing both: non-credentialed scans to map the external attack surface and credentialed scans to validate true risk and ensure deep compliance.
Credentialed vs. Non-Credentialed Scans
Overview In vulnerability discovery and analysis, scans are categorized by the level of access the scanner has to the target system. The primary distinction lies between Credentialed (Authenticated) and Non-Credentialed (Unauthenticated) scans. Choosing the right type depends on the goal of the engagement (Black Box vs. White Box) and the depth of information required.
1. Non-Credentialed Scans (Unauthenticated) A non-credentialed scan operates without privileged access to the target system. The scanner interacts with the target only over the network, mimicking an external attacker with no prior knowledge or accounts.
How it works: The scanner sends packets to the target's IP address and analyzes the responses. It identifies open ports, active services, and banner grabbing information (e.g., identifying 'Apache 2.4.49' from a header).
Characteristics: - Perspective: Simulates an external 'Black Box' attacker. - Depth: Shallow. Can only see what is exposed to the network. - Accuracy: Higher rate of false positives because it guesses vulnerabilities based on service banners rather than verifying installed patches. - Risk: Lower impact on server resources, but may still crash legacy services.
2. Credentialed Scans (Authenticated) A credentialed scan is performed using a valid username and password (or SSH key/agent) that allows the scanner to log into the target system.
How it works: The scanner logs into the OS or application and queries the local system directly. It checks registry keys (Windows), package managers (Linux), file versions, and configuration settings.
Characteristics: - Perspective: Simulates a 'White Box' test, an insider threat, or a compromised account. - Depth: Deep. Can audit permissions, password policies, and specific software patch levels. - Accuracy: Very high accuracy with low false positives. It definitively knows if a patch is installed. - Risk: Higher resource utilization on the host due to active queries, but generally safer than aggressive network probing.
Exam Tips: Answering Questions on Credentialed vs Non-Credentialed Scans When answering CompTIA PenTest+ scenario questions, look for specific triggers to decide which scan is appropriate:
1. 'Reduce False Positives': If a question asks how to get the most accurate results or reduce false positives, the answer is always a Credentialed Scan. 2. 'Validate Patches': If the objective is to verify if a specific patch is applied or to perform a compliance audit, select Credentialed Scan. 3. 'External Attacker Perspective': If the client wants to know what a hacker can see from the internet without inside access, select Non-Credentialed Scan. 4. 'Configuration Audit': Any mention of checking password complexity policies, registry settings, or file permissions requires a Credentialed Scan. 5. 'Missing Results': If a scenario describes a scan that failed to identify known vulnerabilities (like an outdated Flash player installed locally but not running), the scanner likely failed to use credentials.