adzerk.net é seguro?

https://sitecheck.sucuri.net/results/adzerk.net ISSUE DETECTED Outdated Web Server Nginx Found DEFINITION Vulnerabilities on nginx (see URL below) VULNERABLE HEADER nginx/1.1.19 ***** Excerpt: All of the following are coded as MAJOR SEVERITY: SPDY heap buffer overflow SPDY memory corruption Stack-based buffer overflow with specially crafted request Buffer overflow in the ngx_http_mp4_module Memory disclosure with specially crafted backend responses Vulnerabilities with invalid UTF-8 sequence on Windows Vulnerabilities with Windows file default stream Vulnerabilities with Windows 8.3 filename pseudonyms The renegotiation vulnerability in SSL protocol Buffer underflow vulnerability Null pointer dereference vulnerability

I generally block ad servers, but I'm allowing this one a Reddit, and the StackOverflow community next time I'm there. Here's why, from the announcement at Reddit: "Adzerk does provide us some really cool features. For example, if you dislike a particular ad in the sidebar, it is now possible to hide it from showing again. If you hover over a sidebar ad in /r/sports, a new "thumbs up" / "thumbs down" overlay will appear. If you "thumbs down" an ad, we won't display it to you again, and you can give us feedback to improve the quality of reddit ads in the future."