ECCouncil 312-50v12 - Certified Ethical Hacker Exam (CEHv12)

https://book.hacktricks.xyz/pentesting-web/csrf-cross-site-request-forgery

Cross-site request forgery (also known as CSRF) is a web security vulnerability that allows an attacker to induce users to perform actions that they do not intend to perform.

This is done by making a logged in user in the victim platform access an attacker controlled website and from there execute malicious JS code, send forms or retrieve "images" to the victims account.

In order to be able to abuse a CSRF vulnerability you first need to find a relevant action to abuse (change password or email, make the victim follow you on a social network, give you more privileges...). The session must rely only on cookies or HTTP Basic Authentication header, any other header can't be used to handle the session. An finally, there shouldn't be unpredictable parameters on the request.

Several counter-measures could be in place to avoid this vulnerability. Common defenses:

- SameSite cookies: If the session cookie is using this flag, you may not be able to send the cookie from arbitrary web sites.

- Cross-origin resource sharing: Depending on which kind of HTTP request you need to perform to abuse the relevant action, you may take int account the CORS policy of the victim site. Note that the CORS policy won't affect if you just want to send a GET request or a POST request from a form and you don't need to read the response.

- Ask for the password user to authorise the action.

- Resolve a captcha

- Read the Referrer or Origin headers. If a regex is used it could be bypassed form example with:

http://mal.net?orig=http://example.com (ends with the url)

http://example.com.mal.net (starts with the url)

- Modify the name of the parameters of the Post or Get request

- Use a CSRF token in each session. This token has to be send inside the request to confirm the action. This token could be protected with CORS.

Diagram Description automatically generated

A SYN flood attack is a type of denial-of-service (DoS) attack that exploits the TCP handshake process by sending a large number of SYN requests to the target server, without completing the connection. This consumes the connection state tables on the server, preventing it from accepting new connections. The attacker has crafted an automated botnet to simultaneously send ‘s’ SYN packets per second to the server. The server can handle ‘f’ SYN packets per second without any performance issues. If ‘s’ exceeds ‘f’, the network infrastructure begins to show signs of overload. The system’s response time increases exponentially (24k), where ‘k’ represents each additional SYN packet above the ‘f’ limit.

Considering ‘s=500’ and different ‘f’ values, the scenario that is most likely to cause the server to experience overload and significantly increased response times is the one where ‘f=420’. This is because ‘s’ is greater than ‘f’ by 80 packets per second, which means the server cannot handle the incoming traffic and will eventually run out of resources. The response time shoots up (2480 = 281,474,976,710,656 times the normal response time), indicating a system overload.

The other scenarios are less likely or less severe than the one where ‘f=420’. Option A has ‘f=510’, which is greater than ‘s’, so the system stays stable and the response time remains unaffected. Option B has ‘f=495’, which is less than ‘s’ by 5 packets per second, so the response time drastically rises (245 = 32 times the normal response time), indicating a probable system overload, but not as extreme as option D. Option C has ‘f=505’, which is less than ‘s’ by 5 packets per second, so the response time increases but not as drastically (245 = 32 times the normal response time), and the system might still function, albeit slowly. References:

SYN flood DDoS attack | Cloudflare

SYN flood - Wikipedia

What Is a SYN Flood Attack? | F5

What is a SYN flood attack and how to prevent it? | NETSCOUT

Google hacking or Google dorking https://en.wikipedia.org/wiki/Google_hacking

It is a hacker technique that uses Google Search and other Google applications to find security holes in the configuration and computer code that websites are using. Google dorking could also be used for OSINT.

Search syntax https://en.wikipedia.org/wiki/Google_Search

Google’s search engine has its own built-in query language. The following list of queries can be run to find a list of files, find information about your competition, track people, get information about SEO backlinks, build email lists, and of course, discover web vulnerabilities.

- [site:] - Search within a specific website

To start the Computer Management Console from command line just type compmgmt.msc /computer:computername in your run box or at the command line and it should automatically open the Computer Management console.

References: http://www.waynezim.com/tag/compmgmtmsc/

https://en.wikipedia.org/wiki/Lightweight_Directory_Access_Protocol

LDAP, the Lightweight Directory Access Protocol, is a mature, flexible, and well supported standards-based mechanism for interacting with directory servers. It’s often used for authentication and storing information about users, groups, and applications, but an LDAP directory server is a fairly general-purpose data store and can be used in a wide variety of applications.

The LDAP protocol can deal in quite a bit of sensitive data: Active Directory usernames, login attempts, failed-login notifications, and more. If attackers get ahold of that data in flight, they might be able to compromise data like legitimate AD credentials and use it to poke around your network in search of valuable assets.

Encrypting LDAP traffic in flight across the network can help prevent credential theft and other malicious activity, but it's not a failsafe—and if traffic is encrypted, your own team might miss the signs of an attempted attack in progress.

While LDAP encryption isn't standard, there is a nonstandard version of LDAP called Secure LDAP, also known as "LDAPS" or "LDAP over SSL" (SSL, or Secure Socket Layer, being the now-deprecated ancestor of Transport Layer Security).

LDAPS uses its own distinct network port to connect clients and servers. The default port for LDAP is port 389, but LDAPS uses port 636 and establishes TLS/SSL upon connecting with a client.

Sniffing attacks are a type of network attack that involves intercepting and analyzing data packets as they travel over a network. Sniffing attacks can be used to steal sensitive information, such as usernames, passwords, credit card numbers, etc. Sniffing attacks can also be used to perform reconnaissance, spoofing, or man-in-the-middle attacks.

The IT department of the company has implemented some security measures to prevent or mitigate sniffing attacks, such as:

Adding the MAC address of the gateway to the ARP cache: This prevents ARP spoofing, which is a technique that allows an attacker to redirect network traffic to their own device by sending fake ARP messages that associate their MAC address with the IP address of the gateway.

Switching to IPv6 instead of IPv4: This reduces the risk of IP spoofing, which is a technique that allows an attacker to send packets with a forged source IP address, pretending to be another device on the network.

Using encrypted sessions such as SSH instead of Telnet, and Secure File Transfer Protocol instead of FTP: This protects the data from being read or modified by an attacker who can capture the packets, as the data is encrypted and authenticated using cryptographic protocols.

However, these measures are not enough to completely eliminate the threat of sniffing, as an attacker can still use other techniques, such as:

Passive sniffing: This involves monitoring the network traffic without injecting any packets or altering the data. Passive sniffing can be done on a shared network, such as a hub, or on a switched network, using techniques such as MAC flooding, port mirroring, or VLAN hopping.

Active sniffing: This involves injecting packets or modifying the data to manipulate the network behavior or gain access to more traffic. Active sniffing can be done using techniques such as DHCP spoofing, DNS poisoning, ICMP redirection, or TCP session hijacking.

Therefore, the next step to enhance network security is to implement network scanning and monitoring tools, which can help detect and prevent sniffing attacks by:

Scanning the network for unauthorized devices, such as rogue access points, hubs, or sniffers, and removing them or isolating them from the network.

Monitoring the network for abnormal traffic patterns, such as excessive ARP requests, DNS queries, ICMP messages, or TCP connections, and alerting the network administrators or blocking the suspicious sources.

Analyzing the network traffic for malicious content, such as malware, phishing, or exfiltration, and filtering or quarantining the infected or compromised devices.

References:

CEHv12 Module 05: Sniffing

Sniffing attacks - Types, Examples & Preventing it

How to Prevent and Detect Packet Sniffing Attacks

Understanding Sniffing in Cybersecurity and How to Prevent It

These types of attacks occur when faults or glitches are INJECTED into the Power supply that can be used for remote execution.

The best practice to meet the client’s requirement is to encrypt data client-side before uploading to the cloud and retain control of the encryption keys. This practice is also known as client-side encryption or end-to-end encryption, and it involves encrypting the data on the client’s device using a software or hardware tool that generates and manages the encryption keys. The encrypted data is then uploaded to the cloud service, where it remains encrypted at rest. The encryption keys are never shared with the cloud service provider or any third party, and they are only used by the client to decrypt the data when needed. This way, the client can maintain full control over the encryption keys and the security of the data, even when the data is stored on a public cloud service12.

The other options are not as optimal as option D for the following reasons:

A. Use the cloud service provider’s encryption services but store keys on-premises: This option is not feasible because it contradicts the client’s requirement of maintaining full control over the encryption keys. Using the cloud service provider’s encryption services means that the client has to rely on the cloud service provider to generate and manage the encryption keys, even if the keys are stored on-premises. The cloud service provider may have access to the keys or the ability to decrypt the data, which may compromise the security and privacy of the data. Moreover, storing the keys on-premises may introduce additional challenges, such as key distribution, synchronization, backup, and recovery3.

B. Use the cloud service provider’s default encryption and key management services: This option is not desirable because it violates the client’s requirement of maintaining full control over the encryption keys. Using the cloud service provider’s default encryption and key management services means that the client has to trust the cloud service provider to encrypt and decrypt the data on the server-side, using the cloud service provider’s own encryption keys and mechanisms. The cloud service provider may have access to the keys or the ability to decrypt the data, which may compromise the security and privacy of the data. Furthermore, the cloud service provider’s default encryption and key management services may not meet the regulatory requirements or the security standards of the client4.

C. Rely on Secure Sockets Layer (SSL) encryption for data at rest: This option is not sufficient because SSL encryption is not designed for data at rest, but for data in transit. SSL encryption is a protocol that encrypts the data as it travels over the internet between the client and the server, using certificates and keys that are exchanged and verified by both parties. SSL encryption can protect the data from being intercepted or modified by unauthorized parties, but it does not protect the data from being accessed or decrypted by the cloud service provider or any third party who has access to the server. Moreover, SSL encryption does not provide the client with any control over the encryption keys or the security of the data.

References:

1: Client-side encryption - Wikipedia

2: What is Client-Side Encryption? | Definition, Benefits & Best Practices | Kaspersky

3: Cloud Encryption Key Management: What You Need to Know | Thales

4: Cloud Encryption: How It Works and How to Use It | Comparitech

: What is SSL Encryption and How Does it Work? | Norton

Types of Password Attacks - Active Online Attacks: Internal Monologue Attack Attackers perform an internal monologue(獨自) attack using SSPI (Security Support Provider Interface) from a user-mode application, where a local procedure call to the NTLM authentication package is invoked to calculate the NetNTLM response in the context of the logged-on user.Attacker disables the security controls of NetNTLMv1, extracts all the non-network logon tokens from all the active processes to masquerade as legitimate users. (P.594/578)

https://ieeexplore.ieee.org/document/5567385

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