XYMONCGIMSG.CGI(8)

📦 version 4.3.30, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking

💅 XYMONCGIMSG.CGI(8) — the girlies' guide to proxying Xymon data over HTTP

okay so bestie, buckle up, we're reading the xymoncgimsg.cgi manual page (that's section 8 of the System Manager's Manual, iykyk) and honestly? it's giving "small but mighty." let's get into it 🫶

✨ NAME ✨

xymoncgimsg.cgi — the CGI utility you use for proxying Xymon data over HTTP. literally that's her whole job. no cap.

🎀 SYNOPSIS 🎀

xymoncgimsg.cgi

that's it. no flags, no args, no drama. she just exists and does her thing 💅

🌸 DESCRIPTION 🌸

so xymoncgimsg.cgi(8) is the server-side utility, and her whole main character moment is receiving Xymon messages that the xymon(1) utility sent over an HTTP transport. 👑

here's the tea: normally, xymon sends data over its own dedicated TCP protocol. iconic, love that for her. BUT sometimes she's gotta use HTTP instead — like when she needs to get through proxies, or through restrictive firewalls that are being lowkey toxic and blocking everything. 🚧

when that happens? the webserver has to have this CGI utility installed. then she:

  1. receives the message via HTTP, and
  2. forwards it to a local Xymon server through the normal Xymon transport.

so it's giving relay race, but make it network protocols 🏃♀️✨

the CGI expects to be invoked from an HTTP "POST" request, and the POST-data is the status-message. xymoncgimsg.cgi simply collects all of the POST data and sends it off as a message to the Xymon daemon running on IP 127.0.0.1. and bestie, listen — that destination IP currently cannot be changed. periodt. it's not a setting, it's a lifestyle. 🙈

and here's the cute part: the CGI will return any output provided by the Xymon daemon back to the requestor as the response to the HTTP POST. so this means all the normal Xymon commands work. slay 💖

🔒 SECURITY 🔒

okay this is the serious section, bestie, so let's focus up 🧚

  • xymoncgimsg.cgi will only send data to a Xymon server through the loopback interface, i.e. IP-address 127.0.0.1. no wandering off, no talking to strangers on the network.
  • Access to the CGI should be restricted through webserver access controls, because the CGI provides no authentication at all to validate incoming messages. like, zero. none. she trusts everyone and that's a problem 😭
⚠️ no auth means literally anyone who can reach the CGI can shove messages at your Xymon daemon. lock that door with your webserver's access controls, fr fr.

and a lil pro tip that's actually straight from the page: if possible, consider using the xymonproxy(8) utility instead for native proxying of Xymon data between networks. she's the upgrade, the glow-up, the ✨deluxe edition✨

👀 SEE ALSO 👀

the whole friend group. go read them too, bestie, they're all part of the lore 📚💜

and that's the page!! 🎉 this was Xymon Version 4.3.30, dated 4 Sep 2019, from the System Manager's Manual — xoxo, go secure your CGI, mwah 💋🌈⭐

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