Tag Archives: web apps

When HTML Encoding Helped XSS

Recently I was pentesting a web app that had an unauthenticated XSS vulnerability but there was some heavy filtering in place. Nonetheless I was able to achieve session fixation using a combination of a technique I previously explained and some fun filter workarounds – including using the application’s own defensive HTML encoding to create a working XSS payload! Continue reading

SQL Injection in Search Fields

A quick posting about a fun SQL injection I cracked last week (of course, it’s only when you’ve cracked them that they’re fun!). A colleague had found the classic sign of a problem – add a single quote and you get an error – but was having no luck doing anything more. I was getting nowhere with my test so I thought I’d take a look for a change of scene. The input field was in a search box so, for example, search=keyword' returned an error but search=keyword'' was fine. Anything more exciting than that, however, such as search=keyword' and '1'='1, didn’t seem to work as expected: in this case, an error was returned instead of the same set of results that the normal search=keyword produced. Continue reading

Session Fixation and XSS Working Hand-in-Hand

Often a combination of security flaws come together to produce a unique attack vector. Individually the flaws may not amount to much but together they make an interesting combo. This is invariably more interesting from a pentesting point of view because you know that a tool couldn’t positively find it. Session fixation is one such scenario because usually a few requirements must be met for the attack to work. I thought I’d write up a recent session fixation flaw because the act of forcing the cookie onto the victim involved a little twist on overwriting session cookies that made a reflective XSS attack last a lot longer while also laughing in the face of httponly. Continue reading

Three Cheers for DirBuster

Not exactly wizard stuff today, more like back to basics perhaps – but sometimes they’re worth revisiting. I’ve had some good DirBuster finds three tests in a row so I thought I’d write them up as a case study. It’s a reminder that there’s some very low-hanging fruit out there that may not always get picked. I’ve also put together a walk-through for many of DirBuster’s features and I aim to show that, as with many tools, a few minutes of manual work can produce a faster set of more meaningful results. Continue reading