Limiting URLs to scan with wapiti / 2022-08-26

I wanted to use wapiti as scanner to check for other vulnerabilities in The Virtual Bookcase after receiving a report about a cross-site scripting vulnerability. Wapiti is open source and free, which is a fitting price for scanning a hobby project site.

I quickly ran into wapiti taking hours to scan because of the URL structure of the site: all /book/detail/x/y URLs map to one handler that deals with the X and Y parameters in SQL queries. Yes those queries are surrounded by very defensive checking and I use positional parameters. Everything to avoid SQL injection and becoming the next Little Bobby Tables.

Wapiti has no simple method that I can find to crawl for a list of URLs and stop at that to allow for selecting the list of URLs to scan. But it has an option to minimize crawling and import a list of additional URLs to scan so I used that option to get at the same result.

Gathering URLs was done with wget:

$ wget --spider -r http://developer.virtualbookcase.com 2>&1 | grep '^--' | egrep -v '\.(css|jpg|gif|png)' | awk '{ print $3}' > developer.virtualbookcase.com-urls.txt

After that I sorted the file with URLs and threw out a lot of them, making sure all the scripts with several variants of input were still tested.

With that list I start wapiti with some special options. It still needs a starting url at -u so I give it the root but I limit the crawling with the depth parameter -d 1 and the max files parameter --max-files-per-dir 50. Then I add the additional urls from the earlier scan with the -s parameter. It's a lot of tweaking but it does the trick.

$ wapiti -u http://developer.virtualbookcase.com/ -d 1 --max-files-per-dir 50 -s developer.virtualbookcase.com-urls.txt -o ~/wapiti/ -v 2

No vulnerabilities were found. I found one PHP warning which only triggered in the kind of corner case a web vulnerability scanner causes, or an attacker. So I fixed that corner case too.