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4 Most Common Web Security Vulnerabilities


Attack vectors are increasingly exploiting web security vulnerabilities to breach enterprise systems and wreak havoc. However, calculating the cost of a vulnerability in monetary terms alone may not be enough to assess its full impact. A breach's effect on an organization's reputation is just as significant as the financial damage it causes.

According to a vulnerability and threads trend report, new vulnerabilities in operational technology (OT) devices have grown by 46 percent, meaning the frequency of exploitation of web security vulnerabilities has risen by an alarming proportion, necessitating stronger counter-measures.

What is web vulnerability?

Web vulnerability or web security vulnerability is a flaw or misconfiguration in the security framework of a website or a web app. Such vulnerabilities allow threat actors to gain illegitimate authority over the site and the data on it. These threat actors leverage different tools and techniques to scan for weaknesses in a system or application. Once they detect a flaw, they pollute the web app by distributing malicious content, stealing user credentials, or injecting a defacing code. According to an OPSWAT report, a majority of the companies remain concerned about secure file transfers while using a web application for file uploads.

Top 4 Web Security Vulnerabilities

1. SQL Injection

SQL injection is a widely known web security vulnerability, in which threat actors target the application's back-end. The attackers attempt to manipulate the SQL statements through user-supplied data. This way, the attacker attempts to inject unintended commands and tricks the application into divulging sensitive data.

Preventative measures

  • Consistently filter all user input using a strict whitelist

  • Offer the least privilege to all user accounts that use SQL queries to connect to databases within an application

  • Place a REST API in between the front-end and the back-end. Such customized REST APIs build an extra security layer that restricts the front-end users from directly running SQL queries

2. Broken authentication & session

Most websites generate session IDs and session cookies associated with each valid user session. These cookies comprise susceptible user information like ID, passwords, username, contact details, etc. Broken authentication is a vulnerability that attackers exploit to target user accounts when the cookies do not get invalidated, either during logout or when browsers get closed suddenly.

Preventative measures

  • Provide an option for multi-factor authentication for each account login

  • Ensure the application does not expose session ID in the URL

  • Implement proper hashing and salting of passwords

3. Cross-Site Scripting (XSS)

Cross-Site Scripting or XXS vulnerabilities target scripts embedded in a page that is executed on the client-side. These web security vulnerabilities occur when the web app accepts untrusted data and transmits it to the browser without correct validation. The attacker prepares malicious scripts, which the users trigger unintentionally. These malicious scripts help the threat actor gain control over the app or steal sensitive information from the app.

Preventative measures

  • Installing Web Application Firewalls

  • Disabling certain markup elements like <script>, <link>, <object>, and <embed> that enable running scripts

  • Upgrading web browsers as most up-to-date browsers come with an XSS detection and prevention mechanism, which does not allow malicious scripts to run

4. Cross-site Request Forgery (CSRF)

CSRF attacks occur when malicious email, links, or websites make the browser perform operations intended by cybercriminals on a trusted site authenticated by the user. A CSRF attack compels a logged victim to send a generated HTTP request, along with a session cookie, through the browser.

Preventative measures

  • Make sure that the application executes through HTTP/2 or HTTP/3 and not HTTP/1.0. HTTP/2 and 3 are faster and more reliable than HTTP/1.1

  • Double submission cookie practice is another way to protect web apps from CSRF attacks

  • If none of these techniques works, the web app development team should consult cyber security experts like Packetlabs to get a better idea of the current vulnerabilities.


Web security vulnerabilities can result in the theft of user information, loss of data, or even complete control of the web application by the attacker. It is important for companies to be aware of these vulnerabilities and take the necessary measures to protect their web applications.

Looking for support? Contact the Packetlabs team today!