- Assess: The fifth step of the NIST RMF that means to determine if established controls are implemented correctly
- Authorize: The sixth step of the NIST RMF that refers to being accountable for the security and privacy risks that may exist in an organization
- Business continuity: An organization's ability to maintain their everyday productivity by establishing risk disaster recovery plans
- Categorize: The second step of the NIST RMF that is used to develop risk management processes and tasks
- External threat: Anything outside the organization that has the potential to harm organizational assets
- Implement: The fourth step of the NIST RMF that means to implement security and privacy plans for an organization
- Internal threat: A current or former employee, external vendor, or trusted partner who poses a security risk
- Monitor: The seventh step of the NIST RMF that means be aware of how systems are operating
- Prepare: The first step of the NIST RMF related to activities that are necessary to manage security and privacy risks before a breach occurs
- Ransomware: A malicious attack where threat actors encrypt an organization’s data and demand payment to restore access
- Risk: Anything that can impact the confidentiality, integrity, or availability of an asset
- Risk mitigation: The process of having the right procedures and rules in place to quickly reduce the impact of a risk like a breach
- Security posture: An organization’s ability to manage its defense of critical assets and data and react to change
- Select: The third step of the NIST RMF that means to choose, customize, and capture documentation of the controls that protect an organization
- Shared responsibility: The idea that all individuals within an organization take an active role in lowering risk and maintaining both physical and virtual security
- Social engineering: A manipulation technique that exploits human error to gain private information, access, or valuables
- Vulnerability: A weakness that can be exploited by a threat
Frameworks
Guidelines to build plans
NIST frameworks (CSF)
- Govern - strong management of cyber sec risk across the whole org
- Identify - Knowing what's in your network from assests to policies
- Protect - Secure systems like adding firewall rules or removing malware
- Detect - watching logs to detect issues or issues logged by ticket
- Respond - respond to an incident
- Recover - restore files from backups
OWASP
- Open
- Web
- Application
- Security
- Principles
Minimize attack surface
Least privilege / zero trust
Defence in depth, multiple lines of defence. MFA / segregation
Separation of duties. Eg windows admins / network admins / backup admins. No one has full control of the org. We can also look at it like having 3 team members if one gets sick the team is still up
Keep security as simple as possible (
Fix security issues, do root cause analysis and fix for good.
Keeping up to date
Medium
Conferences local and the big ones
Security audit
External and internal
Most will be done internal
We will review and improve se
identify risk
check controls
assess compliance
Security controls
- admin controls - policies
- technical controls - IPS systems
- physical controls - cctv / locks
If we opeerate in the EU and take CC payment then we need to comply with GDPR and PCIDSS.
Log analysis
- Firewall logs - connections / actions / traffic passing through the firewall
- Network logs - Taken from the switches in side getting that east > west traffic
- Server / endpoint logs - User login's / process / etc
SIEM
- Security
- Information
- Event
- Management
The SIEM takes in all the logs from multiple sources. It will create dashboards / graphs / timelines etc.
SOAR
- Security
- Orchestration
- Automation,
- And Response
SIEM types
Self hosted - you have your own server and data storage
Cloud hosted - cloud hosted by your vendor
hybrid -
Splunk / splunk enterprise - cisco purchased it
Chronical - googles cloud native tool
- Chronicle: A cloud-native tool designed to retain, analyze, and search data
- Incident response: An organization’s quick attempt to identify an attack, contain the damage, and correct the effects of a security breach
- Log: A record of events that occur within an organization’s systems
- Metrics: Key technical attributes such as response time, availability, and failure rate, which are used to assess the performance of a software application
- Operating system (OS): The interface between computer hardware and the user
- Playbook: A manual that provides details about any operational action
- Security information and event management (SIEM): An application that collects and analyzes log data to monitor critical activities in an organization
- Security orchestration, automation, and response (SOAR): A collection of applications, tools, and workflows that use automation to respond to security events
- SIEM tools: A software platform that collects, analyzes, and correlates security data from various sources across your IT infrastructure that helps identify and respond to security threats in real-time, investigate security incidents, and comply with security regulations
- Splunk Cloud: A cloud-hosted tool used to collect, search, and monitor log data
- Splunk Enterprise: A self-hosted tool used to retain, analyze, and search an organization's log data to provide security information and alerts in real-time
Playbooks
- SIEM detects events
- Playbooks provide a guide for all staff to follow for each kind of incident
- Playbooks are living documents so they are updated all the time
- We have an incident, we apply the playbook, we review and update with lessons learned .
Networks and security
Before we can secure networks we need to understand how they work
MAC addresses (layer 2 local vlan)
IP's (layer 3 routing to other networks)
LAN small area (small business or home network)
WAN larger area (the internet is one big WAN)
- Hub - just retransmits signals broadcast all traffic everywhere not really used these days as they can cause loops. They are generally cheaper devices and often need to be rebooted regularly.
- layer 2 switch - more intelligent than a hub, has vlans and only sends traffic where it needs to go.
- router - connects multiple networks together
- layer 3 switch - switch and router combined. Many modern devices can do both for example a palo alto firewall can do switching on its ports, routing and firewalling.
- Home ISP device - Often a all in one small device that can do modem/routing/wifi/switching/basic firewalling. This lets home users connect to the ISP network and onto the internet.
- virtual network devices - virtual instances of network devices, we can bring up a virtual firewall in AWS for example
Example traffic flow for small business
User device > switch > firewall > internet > internet routers > destination
Example traffic flow for home connection
User device > WIFI > ISP modem/router > internet > internet routers > destination
Client/Server model
End user devices like computers / laptops / phones are known as clients
Servers are the servers hosting the service s that the clients want to use.
Cloud networks
Instead of having all the network devices and servers on site, companies can move their servers and network devices into the cloud and pay a cloud service provider (CSP).
Some benefits include on demand storage and processing power scaling. Cloud analytics (very useful for ops and security teams)
Software as a service (SaaS) - web applicaitons
Infrastructure as a service (IaaS) - network and server infra
Platform as a service (PasS) - The development platform for the web apps
Just like normal infrastrucre, everything sits on top of the network and servers. None of the apps etc can work unless the infrastructure is working.
Iaas > Paas > SaaS
Data packet
Basic unit of information that travels from one device to another over the network
Basic form of a data packet
header body footer
On most networks data is transferred mostly via TCP/IP
TCP/IP model
- 1 - Network access layer (ethernet / WIFI)
- 2 - Internet layer (IPv4 / IPv6)
- 3 - Transport layer (TCP / UDP)
- 4 - Application layer (HTTP TLS FTP SMTP etc)
ICMP
Ping is the best and worst testing tool. ICMP used by ping is its own protocol. It's useful to testing basic network connectivity but it doesn't follow the same rules as TCP. For example you ping to a site can work but the website may not load because of an application layer issue.
TCP vs UDP
TCP - connections (SYN / SYN-ACK / ACK)
UDP - connectionless (used for voice/video streaming) QUIC MASQUE
OSI model
- Application (HTTP, SMTP etc)
- Presentation (data translation / encryption / compression TLS)
- Session (Session manages open/active connections / reconnection them etc)
- Transport (transport, breaking up data into packets TCP/UDP)
- Network (get frames from data link and send them where to do, routing)
- Data link (macs and frames, NCP HDLC SDLC)
- Physical (cables etc)
TCP/IP model is real world. OSI is more theoretical. Need to be familiar with both.
IPv4 address
19.117.63.126
IPv6 address (32 characters)
684D:111:222:3333:444:555:6:77
All IPv4 addresses were being used up. We had to make IPv6 so there would be enough addresses for ever. So far it seems to have been adopted by service providers. I've not seen IPv6 on the LAN in most orgs. IPv6 addresses are much harder for humans to read and spot in logs.
Types of addresses:
- Public IP - on the internet
- Private IP - On the LAN
- MAC address - hardware address of the network card
Format of IPv4 packet
header 20-60
total 20 - 65535 bytes
- Version (VER): This 4 bit component tells receiving devices what protocol the packet is using. The packet used in the illustration above is an IPv4 packet.
- IP Header Length (HLEN or IHL): HLEN is the packet’s header length. This value indicates where the packet header ends and the data segment begins.
- Type of Service (ToS): Routers prioritize packets for delivery to maintain quality of service on the network. The ToS field provides the router with this information.
- Total Length: This field communicates the total length of the entire IP packet, including the header and data. The maximum size of an IPv4 packet is 65,535 bytes.
- Identification: IPv4 packets can be up to 65, 535 bytes, but most networks have a smaller limit. In these cases, the packets are divided, or fragmented, into smaller IP packets. The identification field provides a unique identifier for all the fragments of the original IP packet so that they can be reassembled once they reach their destination.
- Flags: This field provides the routing device with more information about whether the original packet has been fragmented and if there are more fragments in transit.
- Fragmentation Offset: The fragment offset field tells routing devices where in the original packet the fragment belongs.
- Time to Live (TTL): TTL prevents data packets from being forwarded by routers indefinitely. It contains a counter that is set by the source. The counter is decremented by one as it passes through each router along its path. When the TTL counter reaches zero, the router currently holding the packet will discard the packet and return an ICMP Time Exceeded error message to the sender.
- Protocol: The protocol field tells the receiving device which protocol will be used for the data portion of the packet.
- Header Checksum: The header checksum field contains a checksum that can be used to detect corruption of the IP header in transit. Corrupted packets are discarded.
- Source IP Address: The source IP address is the IPv4 address of the sending device.
- Destination IP Address: The destination IP address is the IPv4 address of the destination device.
- Options: The options field allows for security options to be applied to the packet if the HLEN value is greater than five. The field communicates these options to the routing devices.
Network protocols
A sample flow of a basic connection to a website.
- DNS - lookup IP to domain name www.website.com
- ARP - Find where next hope gateway is towards internet
- TCP - Make a connection to the website IP
- TLS - Setup secure connection between client and server
- HTTPS - Display the webpage in the browser over the TLS connection
WIFI security
IEEE 802.11 is WIFI
WEP (broken) > WPA (transitional) > WPA2 (KRACK attacks still work) > WPA3 (more secure, more complex)
Firewalls
Allow/block traffic based on their rules. The rules are configured by admin.
- Hardware - physical device has its own memory/CPU
- Software - Software imagine which can run in your virtualization infra
- Cloud - Cloud hosted software firewall
stateless - Just applies its rules to traffic but doesn't keep track of connections (less secure
stateful - keeps track of connections and filters threats
ngfw - Does everything stateful does and more (DPI, IPS, Threat intel, content filtering etc)
Firewalls are often the headend for dial in VPNs (remote access for users)
VPNs (virtual private networks)
- Site links are expensive, we can make VPN across the public internet but keep them secure
- S2S VPNs - connect two sites via an encrypted tunnel
- dial in or RA VPNS - remote access VPNs for end users to work from home etc
Security Zones
Before we had interfaces
Now we can have zones where we have multiple interfaces in one zone
Zones are used as part of network segmentation
Outside/internet - uncontroller
Ideally
Internet > firewall > DMZ > firewall > LAN > firewall > Restricted zone
We can have multiple DMZ's / LANs / WIFIs / Restricted zones
Often to cut costs we will just have one firewall with each zone as an interface off the firewall
Internet > firewall > DMZ/LAN/WIFI/Restricted
The firewall controls access between the zones.
To do some network segmentaiton
- Firewall interface (with firewall rules applied)
- Assign it to the inside security zone
- Attach interface to the LAN vlan on the switch
- Create an IP subnet for the LAN network
Proxy servers
The proxy server forwards requests on.
The most common was a web proxy or forward proxy.
user > web proxy > internet
Users never get direct internet access.
Reverse proxy (often socks5) take data from internet/dmz and forwards it to inside servers.
forward: user > proxy > internet
reverse: internet/dmz > proxy > server
Many left behind forward proxies for cisco umbrella / dns protection.
VPN protocols
Wireguard
- code base: 4K lines
- cryptography: fixed modern suite
- High speed vpn
- newer (2016)
- open source
- key-pairs but not built in identity system
IPsec (IKEV2)
- code base: 10K plus
- Earlier protocol (late 1990s)
- More complex
- cryptography: Negotiable, many cipher/algorithm
- Tried and tested, well supported
TLS/DTLS-based VPNs (OpenVPN, Cisco AnyConnect/DTLS, GlobalProtect)
- code base: 10K plus
- In the middle protocol (openvpn 2001, dtls 2006)
- More complex
- cryptography: Negotiable, many cipher/algorithm
- Tried and tested, well supported
Rule-of-thumb selection guidance
- Need it to work everywhere, even hostile networks > TLS/DTLS (OpenVPN-style)
- Need broad native client support with enterprise auth (RADIUS/certs/MFA) > IPsec/IKEv2
- Need maximum speed/efficiency and control both ends > WireGuard (often paired with an identity/ACL layer like Tailscale for enterprise use)
