No, this is about log4j2 which is kinda new (2.0.0 was released 2014). Otherwise, yeah, this is terrible, especially since the tag doesn't even have to be in the formatting string.
> log.info("foo: " + bar);
rather than:
> log.info("foo: {}", bar);
But the issue also affects log4j2, and it doesn't matter which form of logging you use, since the transformation apparently happens further along in some appender, used by both versions of log4j.
log.info("Request User Agent:{}", userAgent);
Also, I just try with log4j1 , and I can't reproduce it. At least with the netcat trick doesn't work : https://twitter.com/thetaph1/status/1469264526214406150?s=20
And yes, I'm actually not sure log4j1 is vulnerable. I assumed it was because the sample code in the post was using log4j1, though the description only explicitly mentions log4j2.