Cybersecurity experts are continuously warning people about the various types of browser attacks that can compromise their personal information and disrupt their online activities. Despite being well-known and having been around for a while, these attacks still work, which is why attackers continue to use them. In this article, we will explore the five common browser attacks, including cross-site scripting (XSS), malicious extensions, session hijacking, DNS poisoning, and man-in-the-middle (MitM) attacks, and discuss preventive measures that users and security teams can take.
One of the most prevalent browser attacks is cross-site scripting (XSS). XSS attacks involve injecting malicious code client-side, usually in the form of JavaScript, HTML, or Visual Basic Script, into a compromised web application or website. This allows attackers to manipulate the victim’s browser, steal user data, or hijack browser sessions. There are three main types of XSS attacks: stored XSS, reflected XSS, and DOM-based XSS. Stored XSS occurs when unsanitized user input is saved by the compromised application or website, potentially executing any embedded script. Reflected XSS happens when a user clicks on a link that contains a malicious payload, which is then displayed through an HTTP response. DOM-based XSS involves the attacker using the DOM API to execute injected code.
To prevent XSS attacks, security teams and developers can take several measures. One option is to use the Content-Security-Policy header, which limits the types of resources that an end user can load from a specific webpage. Enabling the HttpOnly flag ensures that protected cookies cannot be accessed through client-side scripts. Validating user input and implementing an allowlist of acceptable input helps to prevent injection attacks. By cleaning and filtering user input, applications can effectively block potential XSS scripts.
Another common type of browser attack is the use of malicious browser plugins and extensions. These small pieces of code are designed to enhance the browser’s functionality but can be exploited by attackers. Browser extension marketplaces often fail to thoroughly screen extensions, allowing malicious ones to slip through. Malicious extensions can push spam, save user inputs, and inject payloads into browsers. To mitigate this risk, organizations should not allow employees to install browser extensions or plugins on business devices. The value added by an extension rarely outweighs the potential harm it can cause. Furthermore, requiring employees to use an enterprise browser enables organizations to block extension installs. Deploying a tool to inspect browser extensions and plugins can help determine their safety for organizations that do allow employees to install extensions.
Session hijacking is another browser attack that can result in severe consequences for users. During a browsing session, a server assigns a unique session ID to ensure its validity and legitimacy. If this ID is not encrypted, a malicious third party can intercept the browsing session and masquerade as the legitimate user. This allows attackers to steal personal information, infect the user’s device with malware, or even conduct DDoS attacks. To prevent session hijacking, it is crucial to use HTTPS to encrypt data shared between the browser and web server. Enforcing strong password policies and requiring multifactor authentication adds an extra layer of protection. Additionally, using a VPN to encrypt employees’ sessions when accessing the internet over public Wi-Fi or outside the organization’s network, as well as regularly updating and managing software and security patches, are crucial preventive measures.
DNS poisoning is a browser attack where attackers spoof DNS records to redirect users from legitimate websites to fraudulent ones. These fake websites are designed to capture login credentials, steal personal data, or deploy malicious payloads. Users may input their login credentials without realizing that they have been redirected to a fraudulent website. Educating users about not clicking suspicious URLs or downloading email attachments and ensuring that links are HTTPS can help prevent DNS poisoning. Mandating the use of a VPN when connecting to and browsing the internet, implementing end-to-end data encryption, and removing the DNS cache after a suspected DNS poisoning attack are also important preventive measures.
Lastly, man-in-the-middle (MitM) attacks involve cyber attackers inserting themselves between a website or web application and a user’s browser. This allows them to eavesdrop on communications and collect sensitive information such as login credentials. MitM attacks employ various techniques, including IP, DNS, and Address Resolution Protocol spoofing. Encrypted internet traffic, such as using VPNs and public key infrastructure, helps prevent MitM attacks. Additionally, educating users to only visit HTTPS websites, ensuring the URL is correct, and implementing multifactor authentication can further protect against these attacks.
In conclusion, browser attacks continue to be a significant concern in the cybersecurity landscape. Users and security teams must remain vigilant and take appropriate measures to prevent these attacks. By understanding the different types of attacks, such as cross-site scripting, malicious extensions, session hijacking, DNS poisoning, and man-in-the-middle attacks, and implementing preventive measures, individuals and organizations can better protect their online activities and personal information.