CPENT Privilege Escalation Lateral Movement And Post Exploitation — 10 Questions

Question 1

A penetration tester is analyzing a Linux system and finds that the binary /bin/ping has the SUID bit set along with root ownership. What is the security implication of this finding?

Accepted Answer

It allows the binary to execute with the privileges of the file owner (root), which can be exploited if the binary has flaws or drops to a shell.. While ping traditionally required SUID root to open raw sockets, modern Linux kernels support CAP_NET_RAW capability. If a misconfigured SUID binary allows arbitrary command execution, it leads to privilege escalation, but standard SUID ping is typically safe unless a vulnerability exists in that specific version. Let's frame it around exploiting a known SUID binary vulnerability or misconfigured SUID finder.

Answer

It allows remote attackers to execute system calls over ICMP tunneling.

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Any local user can execute commands as root by passing malicious arguments to the SUID binary.

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The system is immune to local privilege escalation because SUID is disabled by SELinux.

Question 2

During an internal engagement, a penetration tester attempts to perform pass-the-hash using Mimikatz, but receives an error indicating that Credential Guard is enabled. Which exploitation technique bypasses this limitation by forcing LSASS to interact with a compromised RPC endpoint?

Accepted Answer

Over-Pass-the-Hash, which generates a full Kerberos ticket using extracted user AES keys instead of NTLM hashes.. When Credential Guard is enabled, direct reading of LSASS memory is blocked. However, techniques like throwing tokens or using restricted administrator access tokens, or abusing specific COM/RPC objects, are alternative vectors, though Pass-the-Ticket via Kerberos delegation or abusing DPAPI are standard workarounds. Specifically, forcing NTLM authentication or abusing constrained delegation are preferred. Wait, the question asks for bypassing Credential Guard or interacting with LSASS - actually, direct LSASS dumping fails, but token impersonation or abusing DCShadow/DCSync if domain admin is available works. For local Credential Guard bypass, Over-Pass-the-Hash (generating Kerberos tickets via AES keys) works if AES keys are extracted from NTDS.dit or kerberos traffic.

Answer

Running mimikatz with the 'privilege::debug' command escalated via a service account.

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Patching the lsass.exe executable on disk to disable security checks.

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Injecting shellcode directly into the winlogon.exe process memory space.

Question 3

A penetration tester is performing post-exploitation on a Linux system and wants to exploit an NFS share with the 'no_root_squash' option enabled. Which of the following steps must the tester perform from their attacking machine to successfully write a SUID shell to the share?

Accepted Answer

Mount the NFS share using sudo privileges, copy /bin/bash to the share, and set the SUID permission using chmod +s.. Because no_root_squash allows root access from remote clients to map to root on the NFS server, the attacker must mount the share as local root (using sudo) and compile a SUID binary or copy /bin/bash with the SUID bit set.

Answer

Modify the /etc/exports file on the remote target directly via standard FTP.

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Mount the NFS share using standard user privileges and create a standard user shell script.

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Log into the NFS server directly via SSH using the exported share credentials.

Question 4

An operator has compromised a Linux server and wants to establish persistence via a Cron job that runs every 5 minutes as the root user. Where should the persistence mechanism be placed to ensure execution without modifying /etc/crontab directly?

Accepted Answer

/etc/cron.d/custom_persistence with the format '* * * * * root /bin/nc ...'. Placing a script in /etc/cron.d/ or directly in the root user's crontab via crontab -e (stored in /var/spool/cron/crontabs/root) achieves persistence. Alternatively, /etc/cron.5mins/ if configured, but /etc/cron.d/ is standard.

Answer

~/.bashrc of the current low-privileged user.

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/etc/init.d/rc.local execution hook.

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/var/www/html/backdoor.php

Question 5

A tester discovers that an internal Windows host has the AlwaysInstallElevated registry key set to 1 in both HKCU and HKLM. How can the tester leverage this misconfiguration to escalate privileges?

Accepted Answer

Generate a malicious MSI file using msfvenom and execute it using msiexec /quiet /qn /i exploit.msi.. AlwaysInstallElevated allows MSI packages to be installed with elevated (NT AUTHORITY\SYSTEM) privileges. The tester can generate a malicious MSI file using msfvenom and install it silently.

Answer

Run a batch script that directly modifies the SAM database registry hive.

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Execute a local exploit targeting the Print Spooler service via named pipes.

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Extract plaintext credentials from the lsass.exe process memory.

Question 6

An operator has compromised an Active Directory domain and wants to establish persistence using a Golden Ticket. What critical piece of information from the domain is required to forge this ticket?

Accepted Answer

The NTLM hash (or AES keys) of the krbtgt service account.. A Golden Ticket is forged using the KRBTGT account's NTLM hash (or AES keys), which allows the attacker to generate valid Kerberos Ticket Granting Tickets (TGTs) for any user.

Answer

The krbtgt account's public SSH key stored in Active Directory.

Answer

The global catalog server IP address and LDAP bind credentials.

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The Domain Administrator's plaintext password.

Question 7

During a post-exploitation phase, a penetration tester wants to perform lateral movement using WMI (Windows Management Instrumentation) from a compromised Windows workstation to a domain controller. Which network port must be accessible through host and network firewalls to initiate the WMI connection?

Accepted Answer

TCP port 135 (RPC Endpoint Mapper). WMI relies on DCOM, which uses RPC. The initial connection to the RPC Endpoint Mapper is made on TCP port 135, after which dynamic high ports are negotiated.

Answer

UDP port 53 (DNS)

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TCP port 445 (SMB)

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TCP port 3389 (RDP)

Question 8

A penetration tester has gained a standard user shell on a Windows machine and wants to check for unquoted service paths. Which PowerShell command should they run to identify services with unquoted paths and spaces in their names without administrative privileges?

Accepted Answer

Get-WmiObject win32_service | select Name, PathName | where { $_.PathName -notlike '"*' -and $_.PathName -like '* *' }. Unquoted service paths can be queried via WMI or PowerShell without admin rights. The Get-WmiObject command querying Win32_Service can filter for paths containing spaces and not enclosed in quotes.

Answer

Get-CimInstance Win32_StartupCommand | Select-Object Name, Command

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sc query state= all | findstr /i "binpath"

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Get-Service | Where-Object { $_.Status -eq 'Running' -and $_.Path -notmatch '"' }

Question 9

During a Windows privilege escalation assessment, a tester discovers that the local 'SeImpersonatePrivilege' is enabled on the current service account token. Which exploitation tool class is best suited for abusing this privilege?

Accepted Answer

Potato family exploits (e.g., PrintSpoofer, RoguePotato) that abuse token impersonation via named pipes.. SeImpersonatePrivilege and SeAssignPrimaryTokenPrivilege allow an attacker to impersonate tokens. Tools like Rotten Potato, RoguePotato, or PrintSpoofer leverage this to escalate to NT AUTHORITY\SYSTEM.

Answer

Mimikatz credential dumper via direct LSASS memory injection.

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PowerView domain enumeration modules.

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Windows Subsystem for Linux (WSL) container breakouts.

Question 10

A penetration tester reviewing a Windows machine identifies that a scheduled task executes a script with administrative privileges, but the script file has weak permissions allowing standard users to modify it. What type of privilege escalation vector does this represent?

Accepted Answer

Insecure Scheduled Task Permissions / Writable Task Executable. If a scheduled task runs as SYSTEM or an admin, and the underlying script or binary is writable by low-privileged users, it represents an insecure file permissions vulnerability leading to privilege escalation when the task triggers.

Answer

Unquoted service path exploitation involving spaces in service binary names.

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DLL Hijacking via PATH environment variable manipulation.

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Kerberoasting against domain service principal names.