VIRTUAL PRIVATE NETWORK AND ITS MAJOR FLAWS
What is Virtual Private Network
A VPN or Virtual Private Network is a method used to add security and privacy to private and public networks, like WiFi Hotspots and the Internet. VPNs are most often used by corporations to protect sensitive data
A virtual private network (VPN) extends a private network across a public network, such as the Internet. It enables users to send and receive data across shared or public networks as if their computing devices were directly connected to the private network, and thus are benefiting from the functionality, security and management policies of the private network. A VPN is created by establishing a virtual point-to-pointconnection through the use of dedicated connections, virtual tunneling protocols, or traffic encryption.
A VPN spanning the Internet is similar to a wide area network (WAN). From a user perspective, the extended network resources are accessed in the same way as resources available within the private network. Traditional VPNs are characterized by a point-to-point topology, and they do not tend to support or connect broadcast domains. Therefore, communication, software, and networking, which are based on OSI layer 2 and broadcast packets, such as NetBIOS used in Windows networking, may not be fully supported or work exactly as they would on a local area network(LAN). VPN variants, such as Virtual Private LAN Service (VPLS), and layer 2 tunneling protocols, are designed to overcome this limitation.
VPNs allow employees to securely access the corporate intranet while traveling outside the office. Similarly, VPNs securely connect geographically separated offices of an organization, creating one cohesive network. VPN technology is also used by individual Internet users to secure their wireless transactions, to circumvent geo-restrictions and censorship, and to connect to proxy servers for the purpose of protecting personal identity and location.
Types of Virtual Private Network
Early data networks allowed VPN-style remote connectivity through dial-up modemsor through leased line connections utilizing Frame Relayand Asynchronous Transfer Mode (ATM) virtual circuits, provisioned through a network owned and operated by telecommunication carriers. These networks are not considered true VPNs because they passively secure the data being transmitted by the creation of logical data streams. They have been replaced by VPNs based on IP and IP/Multiprotocol Label Switching (MPLS) Networks, due to significant cost-reductions and increased bandwidth provided by new technologies such as Digital Subscriber Line (DSL) and fiber-optic networks.
VPNs can be either remote-access (connecting a computer to a network) or site-to-site (connecting two networks). In a corporate setting, remote-access VPNs allow employees to access their company’s intranet from home or while traveling outside the office, and site-to-site VPNs allow employees in geographically disparate offices to share one cohesive virtual network. A VPN can also be used to interconnect two similar networks over a dissimilar middle network; for example, two IPv6 networks over an IPv4 network.
VPN systems may be classified by:
- The protocols used to tunnel the traffic
- The tunnel’s termination point location, e.g., on the customer edge or network-provider edge
- Whether they offer site-to-site or network-to-network connectivity
- The levels of security provided
- The OSI layer they present to the connecting network, such as Layer 2 circuits or Layer 3 network connectivity
Security Mechanisms
VPNs cannot make online connections completely anonymous, but they can usually increase privacy and security. To prevent disclosure of private information, VPNs typically allow only authenticated remote access using tunneling protocols and encryptiontechniques.
The VPN security model provides:
- Confidentiality such that even if the network traffic is sniffed at the packet level (see network sniffer and Deep packet inspection), an attacker would only see encrypted data
- Sender authentication to prevent unauthorized users from accessing the VPN
- Message integrity to detect any instances of tampering with transmitted messages
Secure VPN protocols include the following:
- Internet Protocol Security (IPsec) as initially developed by the Internet Engineering Task Force (IETF) for IPv6, which was required in all standards-compliant implementations of IPv6 before RFC 6434 made it only a recommendation. This standards-based security protocol is also widely used with IPv4 and the Layer 2 Tunneling Protocol. Its design meets most security goals: authentication, integrity, and confidentiality. IPsec uses encryption, encapsulating an IP packet inside an IPsec packet. De-encapsulation happens at the end of the tunnel, where the original IP packet is decrypted and forwarded to its intended destination.
- Transport Layer Security (SSL/TLS) can tunnel an entire network’s traffic (as it does in the OpenVPN project and SoftEther VPN project) or secure an individual connection. A number of vendors provide remote-access VPN capabilities through SSL. An SSL VPN can connect from locations where IPsec runs into trouble with Network Address Translation and firewall rules.
- Datagram Transport Layer Security (DTLS) – used in Cisco AnyConnect VPN and in OpenConnect VPN to solve the issues SSL/TLS has with tunneling over UDP.
- Microsoft Point-to-Point Encryption (MPPE) works with the Point-to-Point Tunneling Protocol and in several compatible implementations on other platforms.
- Microsoft Secure Socket Tunneling Protocol (SSTP) tunnels Point-to-Point Protocol (PPP) or Layer 2 Tunneling Protocol traffic through an SSL 3.0 channel. (SSTP was introduced in Windows Server 2008 and in Windows Vista Service Pack 1.)
- Multi Path Virtual Private Network (MPVPN). Ragula Systems Development Company owns the registered trademark “MPVPN”.
- Secure Shell (SSH) VPN – OpenSSH offers VPN tunneling (distinct from port forwarding) to secure remote connections to a network or to inter-network links. Tunnel endpoints must be authenticated before secure VPN tunnels can be established. User-created remote-access VPNs may use passwords, biometrics, two-factor authentication or other cryptographicmethods. Network-to-network tunnels often use passwords or digital certificates. They permanently store the key to allow the tunnel to establish automatically, without intervention from the administrator.
Routing
Tunneling protocols can operate in a point-to-point network topologythat would theoretically not be considered as a VPN, because a VPN by definition is expected to support arbitrary and changing sets of network nodes. But since most router implementations support a software-defined tunnel interface, customer-provisioned VPNs often are simply defined tunnels running conventional routing protocols.
Privacy vulnerability exposes VPN users’ real IP addresses
A major security flaw which reveals VPN users’ real IP addresses has been discovered by Perfect Privacy (PP). The researchers suggest that the problem affects all VPN protocols, including IPSec, PPTP and OpenVPN.
VPN users use the tool to hide their computer’s IP address online, commonly at platforms such as BitTorrent. However, PP now claims that their real identities can easily be unmasked, posing huge potential privacy and legal risks.
The technique involves a port-forwarding tactic whereby a hacker using the same VPN as its victim can forward traffic through a certain port, which exposes the unsuspecting user’s IP address. This issue persists even if the victim has disabled port forwarding.
“We have discovered a vulnerability in a number of providers that allows an attacker to expose the real IP address of a victim. ‘Port Fail’ affects VPN providers that offer port forwarding and have no protection against this specific attack,” PP explained in a blog post yesterday. It reassured its customers that all PP users are protected from the attack.
The only requirement is that the attacker has port forwarding enabled on the same VPN network as its target. A phishing link or laced image file, for example, is then sent to the victim which leads the traffic to a port under the hacker’s control.
PP discovered that five out of nine prominent VPN providers that offer port forwarding were vulnerable to the attack. The company has since notified the affected before disclosing the vulnerability publicly.
Having only carried out limited tests, PP expects that there remains a potential threat through this security flaw across other VPN providers.
To mitigate the attack, PP suggests that VPN companies should implement firewall rules at the VPN server level in order to block access to forwarded ports from users’ real IP addresses.
A Major VPN Flaw Exposes Users’ Real IP Addresses
Major VPN flaw has just been discovered and according to a recent research, VPN users now risk exposing their real IP address. The newly discovered flaw, if exploited, can expose a user’s real IP address and identity. People around the world use Virtual Private Networks to hide their IP addresses, protect their privacy and stay secure on the internet but according to the research by Perfect Privacy, this flaw may be exploited by hackers, censorship agencies, cyber criminals and authorities to detect a user’s real IP address, defeating the main purpose of VPN usage.
Due to censorship laws in different countries around the world, VPN usage has been on the rise. Many users too who prefer to keep their identity private now use Virtual Private Networks. According to Perfect Privacy:
The crucial issue here is that a VPN user connecting to his own VPN server will use his default route with his real IP address, as this is required for the VPN connection to work. If another user (the attacker) has port forwarding activated for his account on the same server, he can find out the real IP addresses of any user on the same VPN server by tricking him into visiting a link that redirects the traffic to a port under his control.
If your VPN provider offers port forwarding and has no protection against this specific attack, you stand the risk of exposing your real IP address. A lot of providers are affected with by flaw. This is how it works: A victim’s real IP address can easily get exposed if a potential attacker uses the same VPN as the victim and traffic is being forwarded on a specific port. According to Perfect Privacy, there’s a way to fix this which VPN providers should employ:
- Have multiple IP addresses, allow incoming connections to ip1, exit connections through ip2-ipx, have port forwardings on ip2-ipx
- On Client connect set server side firewall rule to block access from Client real IP to portforwardings that are not his own.
A lot of providers are already fixing this but if your provider still isn’t doing anything, now may be a good time to inform them.
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