I used to be a big fan of giant ASCII art in log files, and I still like to include a big banner on server startup, but most of the cloud logging solutions like Splunk and the ELK stack don’t really handle big ASCII pictures in the middle of the log.
I was working at a big bank about ten years ago where we had a half-assed poorly implemented compute grid — some customization of a terrible IBM product. For viewing logs across all machines we had a home grown web app which would allow you to navigate through them. I realized the app didn’t sanitize the log output for display, and I started to include animated gifs and memes into my error messages. My boss told me to cut it out, I said, no, someone should fix the log viewer. It took me about an hour to fuzz inputs on our customer facing application that would generate a server error log which could execute arbitrary JavaScript on our machines. The log viewer got fixed.
I was working at a big bank about ten years ago where we had a half-assed poorly implemented compute grid — some customization of a terrible IBM product. For viewing logs across all machines we had a home grown web app which would allow you to navigate through them. I realized the app didn’t sanitize the log output for display, and I started to include animated gifs and memes into my error messages. My boss told me to cut it out, I said, no, someone should fix the log viewer. It took me about an hour to fuzz inputs on our customer facing application that would generate a server error log which could execute arbitrary JavaScript on our machines. The log viewer got fixed.