What is a Reverse Proxy Server? | NGINX
A proxy server is a go‑between or intermediary server that forwards requests for content from multiple clients to different servers across the Internet. A reverse proxy server is a type of proxy server that typically sits behind the firewall in a private network and directs client requests to the appropriate backend server. A reverse proxy provides an additional level of abstraction and control to ensure the smooth flow of network traffic between clients and servers.
Common uses for a reverse proxy server include:
Load balancing – A reverse proxy server can act as a “traffic cop, ” sitting in front of your backend servers and distributing client requests across a group of servers in a manner that maximizes speed and capacity utilization while ensuring no one server is overloaded, which can degrade performance. If a server goes down, the load balancer redirects traffic to the remaining online servers.
Web acceleration – Reverse proxies can compress inbound and outbound data, as well as cache commonly requested content, both of which speed up the flow of traffic between clients and servers. They can also perform additional tasks such as SSL encryption to take load off of your web servers, thereby boosting their performance.
Security and anonymity – By intercepting requests headed for your backend servers, a reverse proxy server protects their identities and acts as an additional defense against security attacks. It also ensures that multiple servers can be accessed from a single record locator or URL regardless of the structure of your local area network.
How Can NGINX Plus Help?
NGINX Plus and NGINX are the best-in-class load‑balancing solutions used by high‑traffic websites such as Dropbox, Netflix, and Zynga. More than 400 million websites worldwide rely on NGINX Plus and NGINX Open Source to deliver their content quickly, reliably, and securely.
As a software‑based reverse proxy, not only is NGINX Plus less expensive than hardware‑based solutions with similar capabilities, it can be deployed in the public cloud as well as in private data centers, whereas cloud infrastructure vendors generally do not allow customer or proprietary hardware reverse proxies in their data centers.
The Difference Between Proxy and Reverse Proxy | strongDM
Many businesses use proxy servers to route and secure traffic between networks. There’s often confusion, however, on how this differs from a reverse proxy. In this post, we’ll dissect the two concepts and explain how administrators can use a reverse proxy for easy access management is a proxy server? A proxy server, sometimes referred to as a forward proxy, is a server that routes traffic between client(s) and another system, usually external to the network. By doing so, it can regulate traffic according to preset policies, convert and mask client IP addresses, enforce security protocols, and block unknown stems with shared networks, such as business organizations or data centers, often use proxy servers. Proxy servers expose a single interface with which clients interact without having to enforce all of the policies and route management logic within the clients is a reverse proxy? A reverse proxy is a type of proxy server. Unlike a traditional proxy server, which is used to protect clients, a reverse proxy is used to protect servers. A reverse proxy is a server that accepts a request from a client, forwards the request to another one of many other servers, and returns the results from the server that actually processed the request to the client as if the proxy server had processed the request itself. The client only communicates directly with the reverse proxy server and it does not know that some other server actually processed its request. A traditional forward proxy server allows multiple clients to route traffic to an external network. For instance, a business may have a proxy that routes and filters employee traffic to the public Internet. A reverse proxy, on the other hand, routes traffic on behalf of multiple servers. A reverse proxy effectively serves as a gateway between clients, users, and application servers. It handles all the access policy management and traffic routing, and it protects the identity of the server that actually processes the verse proxy configurationBy routing client traffic through a reverse proxy, admins can simplify security administration. They can configure backend servers to only accept traffic directly from the proxy and then configure the granular access control configurations on the proxy example, admins can configure the reverse proxy’s firewall to whitelist or blacklist specific IP addresses. All existing servers behind the proxy will be protected accordingly, and whenever admins add a new backend server to the network that is configured to only accept requests from the proxy server, the new backend server is protected according to the proxy configuration. Using a reverse proxy can also allow administrators to easily swap backend servers in and out without disrupting traffic. Because clients interact directly with the proxy, they only need to know its host name and don’t need to worry about changes to the backend network topology. In addition to simplifying client configuration, an admin can configure a reverse proxy to load-balance traffic so that requests can be more evenly distributed to the backend servers and improve overall case: onboarding and off-boardingWhen onboarding a new user to a network, administrators must configure access control and firewalls to ensure the user can access the appropriate resources. Traditionally, an admin has to configure each server for which users need access. In a large organization with many servers, this can be a time-consuming and error-prone process. However, with a reverse proxy, administrators can configure the access rights directly on the proxy server and have the user route all traffic through it. As such, the backend servers only need to trust and communicate with the proxy directly. This greatly simplifies the configuration process and helps ensure access is granted and revoked correctly by doing so through a single tting up a reverse proxy for access managementWhile a reverse proxy can greatly simplify the process of managing access to a network, setting it up and configuring it properly can get complicated. It requires provisioning the host with appropriate specifications, configuring the operating system and firewall, deciding on which proxy software to use (such as NGINX or HAProxy), enumerating and configuring the downstream servers in the proxy configuration files, setting up audit logging, and configuring the firewalls in all the downstream servers. An administrator will need to optimize the proxy software to adjust for performance and availability requirements. For example, when a downstream server fails, the admin should configure the proxy server to quickly reroute traffic to avoid scale, the out-of-the-box configurations are rarely sufficient, so testing becomes important. Whenever the configurations change, you’ll need a way to run sufficient load against a representative test environment and closely monitor the impact on both performance and availability to verify that configurations will meet the needs of the production ing a reverse proxy by hand vs. buying softwareGiven all the steps involved in implementing, testing, and optimizing a reverse proxy, you may choose to buy software that can provide this functionality without all the custom work. Access management software can provide all of this functionality while also managing the ongoing maintenance and user management. In addition to providing standard reverse proxy capabilities, access management software affords a number of unique benefits:1) Flexibility with user access. By abstracting away the complexity of firewalls and access control, access management software can provide higher-level concepts like user groups. This functionality makes it easy for admins to assign and remove users from various predefined groups and allows the software to automatically implement the access policies. 2) Designed to boost reliability. In distributed systems, servers can fail and network interruptions may occur. Access management software easily detects failed servers and reroutes traffic to working ones to avoid any noticeable downtime for users. 3) Load balancing capabilities. Single servers may struggle when hit with a large amount of traffic, which degrades performance and increases request latency. Access management software can help to manage traffic and balance the load across all servers, making sure it’s evenly naging access with strongDMThe strongDM control plane is a proxy-based solution that simplifies authentication and authorization for admins. It routes all database and server connections through its protocol-aware proxy over a TLS 1. 2 secure TCP connection, and it handles load balancing and automatic failover to provide high availability. The proxy validates user sessions and permissions and then intelligently routes the session to the target database or server through the most efficient path, logging all traffic along the rongDM extends the single sign-on capabilities of your identity provider, allowing you to authenticate users to any server or database. From the Admin UI, you can view connected resources and manage role-based access control for your users. See for yourself with a free, 14-day trial. this post? Then get all that SDM goodness, right in your you! Your submission has been received! Oops! Something went wrong while submitting the form.
Security Reverse Proxy
Web applications vulnerabilities are increasingly being used by attackers to compromise systems on the internet. This has created demand for a mechanism to secure web application without rewriting the whole application. In this article, we see how a security reverse proxy can be used to provide reasonable security for web applications in an organization.
Firewalls, intrusion detection systems and regular patching of servers have secured the servers at the network layer. However, vulnerabilities in web applications are being used by attackers to obtain unauthorized access to critical data, become administrators of applications and even obtain access to the underlying operating system. The attacks are generally carried out by manipulating the requests to the web server.
Applications with vulnerabilities continue to exist on the internet due to the following factors:
The security needs for applications were not considered during the design phase of application development.
The developer community is not fully aware of the security best practices to avoid the application vulnerabilities.
For existing applications, the task of identifying vulnerabilities and correcting them is a long process with large cost implications. This can also result in downtime for business critical applications.
One method of securing applications is by introducing a component which is capable of detecting and blocking attacks, between the client and the web server. A security reverse proxy is such a device. Using it, multiple web applications in an organization can be protected against application level attacks.
What is a Security Reverse Proxy
We have all come across an internet proxy used for accessing the Internet. Internally, the proxy accepts our request and then reinitiates a connection to the internet on our behalf. The proxy obtains the reply from the server and forwards it to the client that requested it. In other words, a regular proxy acts on behalf of a client.
A reverse proxy on the other hand acts on behalf of a server. The reverse proxy accepts the connection from the client and forwards it to the server. It also receives the response from the server and forwards it to the client. A security reverse proxy helps in protecting applications by inspecting the requests for malicious requests. On finding malicious content in the request, the reverse proxy will simply drop the request. The security reverse proxy checks for malicious content using a database which contains a set of allowed or disallowed content.
Detailed working of the Reverse Proxy
The working of a security reverse proxy can be understood by different activities that it carries out on receiving a request. All reverse proxies perform three basic operations:
Request URL remapping: The client makes the request assuming that the reverse proxy is the web server. Before the reverse proxy can forward the request to the internal web server, the URL of the request needs to remapped to reflect the internal server’s URL.
Request Header Remapping: In addition to the URL, some of the headers also need to be rewritten to reflect the internal web server. One such HTTP header is the “Host:” header which carries the hostname from which the URL is requested.
Response Header Remapping: The response from the server also needs to be modified for the client to work correctly. This includes the “Location:” field which contains the location of the file on the above three functions are carried out by all reverse proxies. The additional functions performed by a security reverse proxy are:
Request Content Validation: The security reverse proxy inspects the request for malicious content. The check is actually performed by comparing the request against a database of filter signatures. These signatures are usually constructed using regular expressions. The decision to allow or disallow a request using filter signatures can be implemented either by using a black list or a white list approach. A black list filter contains the known malicious requests. Each request is checked against the entries in the list and blocked if a match is found. Variations of the same attacks need to be captured independently in the list. Thus by using black lists, only known attacks can be blocked. Its effectiveness lies in the comprehensiveness of the black list. A white list filter contains the entire set of valid requests for a particular site. Thus, the white list stops attacks since it allows only known requests to reach the server. The process of creating a white list, however, is very tedious and needs the knowledge of the complete set of valid requests that can possibly be made to a server. Any changes to a protected web application would need a corresponding change to the white list. The process of maintaining a white list thus adds an administrative overhead.
Response Content Validation: The response obtained from the server is also validated before the reverse proxy sends it back to the client. This is usually done using a black list approach. This can be used to block known responses which the client does not need to see. Error messages are one such type of information – the reverse proxy can replace the actual error with a generic error message which does not contain any sensitive information.
Request and response logging: The request can also be logged by the reverse proxy for later analysis. The best approach is to configure logging of only the requests that were blocked. In the initial phases of the implementation, the logs should be closely reviewed. This is required to ensure that valid requests are not getting blocked by the reverse proxy.
Advantages of the reverse proxy
A security reverse proxy offers the following direct benefits:
Using a combination of white and black lists, web severs can be effectively protected against application attacks to a large extent.
The information flowing back to the client can be reviewed and sensitive information can be stopped from reaching the client.
The reverse proxy becomes a single point of entry for the different web applications in the organization. The web servers stay hidden and thus protected from the Internet.
Security monitoring such as log review can performed form a single point. This can improve the chances of detection of attacks to the servers.
The reverse proxy can act as a single SSL server. This can be a big advantage if an organization runs multiple SSL enabled sites. A single SSL server can offer administrative and cost benefits to the organization.
The reverse proxy can also act as caching server for the static content hosted by the organization, thereby improving overall performance of all the web servers.
The system performance and system resource requirements can be better managed and utilized.
Disadvantages
Creation and maintenance of the signature database (white lists and black lists) are complex and time consuming processes. Wrong signatures can block valid requests and create hardships for users of the system.
Any changes or additions in the application will also have to be reflected in the reverse proxy configuration.
The blacklist may not be able block all possible attacks, especially variations.
The reverse proxy may not be able to protect logic issues in the application, such as vulnerabilities in session maintenance.
The reverse proxy becomes a ‘single point of failure’, hence redundancy needs to be considered for the reverse proxy. This will add further complexities to the architecture.
Poor configuration and vulnerabilities of the reverse proxy itself can add another point of vulnerability for the attackers.
Conclusion
Application level vulnerabilities are increasingly being used by attackers to compromise data and servers in the internet. A reverse proxy can be used to secure multiple web servers in an organization from web application vulnerabilities. The reverse proxy also provides additional benefits including hiding of the web servers and improved performance. It also provides a single point for web application logging and analysis. However, maintaining a security proxy will increase the administrative overhead. The increased overheads of a security reverse proxy should be an acceptable price for the assurance obtained against web application vulnerabilities.
Links
RealSentry
Web Security Appliance With Apache and mod_security
Frequently Asked Questions about reverse proxy provides
What is the difference between proxy and reverse proxy?
A traditional forward proxy server allows multiple clients to route traffic to an external network. … A reverse proxy, on the other hand, routes traffic on behalf of multiple servers. A reverse proxy effectively serves as a gateway between clients, users, and application servers.Mar 31, 2021
How does reverse proxy help with security?
The reverse proxy accepts the connection from the client and forwards it to the server. … A security reverse proxy helps in protecting applications by inspecting the requests for malicious requests. On finding malicious content in the request, the reverse proxy will simply drop the request.May 15, 2005
Does reverse proxy provides remote access?
Two technologies frequently used to provide remote access are HTTP reverse proxies and full tunnel VPNs.Jan 21, 2016
