In a previous blog post where I covered Cross-Site Request Forgery and what potential impacts and consequences such an attack may have, I wrote that a popular way to prevent such an attack from unfolding is to generate tokens. In that blog post, I noted that when a website generates tokens, a CSRF attack might be stopped. One thing I did not cover though is that whether the attack will be stopped or not depends on how the tokens are implemented. Confused?…
Your friend creates a website. You are curious and you ask him: “is it secure?”, which, in your mind, probably means “did you secure your website to the best of your abilities?” and your friend replies: “Yes, it has bank-grade security”. Oh, “bank grade security”, damn! That means it’s very secure! Before you intervene, I am by no ways stating that banking websites are insecure – I am interested in how banks and other financial institutions deal with passwords though….
How does a server know when a new header begins and the old one ends or when a line is terminated? Simple. In order to note the termination of a line, \r\n or %0D%0A characters are used. These characters refer to Carriage Return (\r) Line Feed (\n). The characters can (and are) used in HTTP responses. To note the end of a line, they can also be used in files. Is it dangerous? A Carriage Return Line Feed (CRLF) Injection vulnerability occurs…
Another day, another web application gets hacked. Most of the time web application hacks fly under the radar and are discovered years after the data breach occurred, but every so often, after learning what had happened, website administrators hire computer forensic experts in order to help reconstruct and solve high-tech (computer-related) crimes. Every computer forensic expert (or a team of computer forensic experts) has different methods of approaching and solving the problem – but in many cases, the very first thing computer…
Attacks on today’s web are an unsurprising reality – websites are hacked daily, data is being stolen and leaked left, right and centre. In many (though not all) cases, attacks on web applications are successful because a targeted web application is susceptible to security vulnerabilities – vulnerabilities which derive from its components. In the penultimate segment of the 2017 OWASP Top 10 series, I will cover how using components with known vulnerabilities can affect your web application, tell how such risks are…
When developing a web application, web developers sometimes need to first turn data into a proper format so that it can be processed. Occasionally, converting data into a proper format is a requirement in order for it to be stored in a file, database or simply to boost effectiveness. Here’s where serialization comes in – serialization in web applications covers turning data into a stream of bytes so that it can be, for example, stored in a database or in a…
We have all seen search forms, haven’t we? Take a look at mine: The above search form is pretty basic – when a search query is provided, the page will respond with “You’ve searched for …” and display the results. This search form does not have anything unusual compared to the other search forms out there – except that it does not sanitize the input.. What happened here is we have entered a different search term. Here’s what was provided: <script>alert(“2017…
Web applications can be susceptible to all sorts of vulnerabilities: a web application can be vulnerable to at least one of the 2017 OWASP Top 10 vulnerabilities, it can have remote or local file inclusion flaws or be vulnerable to other types of weaknesses. A web application can even be compromised by utilizing social engineering – there are all sorts of ways. With that being said, web applications can also be configured in ways that make them vulnerable. Such a vulnerability is…
Let’s take a scenario like so: I have a web application that allows people to buy software I created – after a person has bought the software, an account must be made. After the individual creates an account, the software can be downloaded. After the purchase, the customer is also granted access to some resources available exclusively to customers. Should any issues arise, support tickets can be lodged. Now imagine you’re an attacker who wants to gain access to the resources available…
Ever processed XML files in your web application? If you did, you probably parsed their contents. And if you parsed their contents, your web application might have been vulnerable to an attack known as XML External Entities (XXE). What is XXE? An XXE attack is a security vulnerability often found in XML parsers. An XML External Entities attack often exploits the XML parsing functionality in a web application making it parse data of interest to an attacker. How does it…