Attack

/ˌɛks-ɛs-ˈɛs/

n. “Sneaky scripts slipping where they shouldn’t.”

XSS, short for Cross-Site Scripting, is a class of web security vulnerability that allows attackers to inject malicious scripts into web pages viewed by other users. Unlike server-side attacks, XSS exploits the trust a user has in a website, executing code in their browser without their consent or knowledge.

There are three main types of XSS: Reflected, Stored, and DOM-based. Reflected XSS occurs when malicious input is immediately echoed by a web page, such as through a search query or URL parameter. Stored XSS involves the attacker saving the payload in a database or message forum so it executes for anyone viewing that content. DOM-based XSS happens when client-side JavaScript processes untrusted data without proper validation.

A classic example: a user clicks on a seemingly normal link that contains JavaScript in the query string. If the website fails to sanitize or escape the input, the script runs in the victim’s browser, potentially stealing cookies, session tokens, or manipulating the page content. XSS attacks can escalate into full account takeover, phishing, or delivering malware.

Preventing XSS relies on a combination of techniques: input validation, output encoding, and content security policies. Frameworks often include built-in escaping functions to ensure that user input does not become executable code. For example, in HTML, characters like < and > are encoded to prevent interpretation as tags. In modern web development, using libraries that automatically sanitize data, alongside Content Security Policy, greatly reduces risk.

XSS remains one of the most common vulnerabilities in web applications, making awareness critical. Even large, popular sites can fall victim if validation and sanitization practices are inconsistent. Testing tools, such as automated scanners, penetration tests, and bug bounty programs, often prioritize XSS detection due to its prevalence and impact.

In essence, XSS is about trust and control. Users trust a website to deliver content safely; attackers exploit that trust to execute unauthorized scripts. Proper sanitization, rigorous coding practices, and security policies are the antidotes, turning a website from a potential playground for malicious scripts into a secure, trustworthy environment.

/ˌdiː-diː-ˈoʊ-ɛs/

n. “When too many people knock at once and the door falls off.”

DDoS, short for Distributed Denial of Service, is a type of cyber attack where multiple systems—often compromised computers, IoT devices, or botnets—flood a target server, network, or service with massive amounts of traffic. The goal isn’t necessarily to steal data or break encryption; it’s to overwhelm resources, disrupt normal operation, and make services unavailable to legitimate users.

Unlike a standard DoS attack, which might originate from a single source, a DDoS leverages thousands or even millions of devices acting in concert, making it harder to block or filter. Modern attacks can combine multiple methods, such as volumetric floods, protocol exploits, and application-layer attacks, to maximize impact and bypass traditional defenses.

For example, a website serving millions of visitors could be taken offline by a DDoS attack sending an overwhelming number of HTTP requests. Similarly, gaming networks, financial services, or government sites are often targeted to cause disruption, financial loss, or reputational damage. Attackers might also use DDoS as a smokescreen for more invasive actions like data theft or malware deployment.

Mitigating DDoS requires multiple strategies. Cloud-based scrubbing services, rate-limiting, traffic analysis, and redundancy are common methods. For instance, routing traffic through a service that identifies and drops malicious requests allows legitimate users to continue using a site even during an attack. Understanding the scale and type of attack is critical: volumetric floods differ from protocol exhaustion or targeted application-layer attacks.

DDoS is also a reminder of the importance of resilient design. Redundant servers, content delivery networks (CDNs), and robust firewall rules can reduce the impact. For developers, engineers, and network admins, monitoring unusual traffic patterns and implementing automated defenses is essential to stay ahead of attackers.

Historically, DDoS attacks have ranged from small-scale pranks to massive outages affecting millions. High-profile incidents, such as the 2016 attack on Dyn, illustrate the potential scale and collateral damage, where a single misconfigured IoT botnet brought down major websites across the internet.

In short, DDoS is less about breaking things permanently and more about temporary chaos—an orchestrated flood that tests the limits of infrastructure and preparation. It emphasizes why cybersecurity isn’t just about encryption, hashing like MD5 or SHA256, or secure authentication like HMAC, but also about resilience, monitoring, and the ability to survive the digital equivalent of a stampede.