# Well Known
This task was part of the 'Web' category at the 2020 Hexion CTF (during 11-13 April 2020).It was solved by [The Maccabees](https://ctftime.org/team/60231) team.
# The challenge
Description:
```Well... it's known (:https://wk.hexionteam.com```
When entering the website, we get a 404 error code.
The challenge name and description indicates this has some connections to [RFC8615](https://tools.ietf.org/html/rfc8615) - which defines a path prefix in HTTP(S) URIs for these "well-known locations", "/.well-known/".This wikipedia page lists all the possible well-known URIs: [List of /.well-known/ services offered by webservers](https://en.wikipedia.org/wiki/List_of_/.well-known/_services_offered_by_webservers).
So we just iterated over all of them in this python script:
```python#!/usr/bin/env pythonimport requestsdomain = "https://wk.hexionteam.com/.well-known/{}"well_known_uris = [    "acme-challenge",    "ashrae",    "assetlinks.json",    "caldav",    "carddav",    "coap",    "core",    "csvm",    "dnt",    "dnt-policy.txt",    "est",    "genid",    "hoba",    "host-meta",    "host-meta.json",    "http-opportunistic",    "keybase.txt",    "mercure",    "mta-sts.txt",    "ni",    "openid-configuration",    "openorg",    "pki-validation",    "posh",    "reload-config",    "repute-template",    "resourcesync",    "security.txt",    "stun-key",    "time",    "timezone",    "uma2-configuration",    "void",    "webfinger",    "apple-app-site-association",    "apple-developer-merchantid-domain-association",    "browserid",    "openpgpkey",    "autoconfig/mail",    "change-password",    "nodeinfo", ]
for well_known_uri in well_known_uris:    d = domain.format(well_known_uri)    r = requests.get(d)    if r.status_code != 404:        print(well_known_uri)```
The script returned two results:
```http-opportunisticsecurity.txt```
When browsing to the `security.txt` URI, we get the flag!
```Flag: hexCTF{th4nk_y0u_liv3_0v3rfl0w}```