You may be able to update the firmware on that OEM SSD, but you'll need to verify a few things first. It is possible to purchase "OEM" packaged SSD at the usual retail level, I've done so myself, including a X-25M. The firmware on the SSD from the factory is printed on the label, so if you can see that you'll know what firmware came with the SSD.
IMO, I tend to doubt that any manufacture purchasing a ready to use SSD would modify or develop their own firmware, that is done by manufactures that assemble SSDs from parts to sell at retail, if they even change it at all. This SSD is one of Intel's second generation models, early in the history of SSDs, and anyone thinking they could do better than the standard firmware was crazy, which is why I doubt it was changed by anyone (if Intel would even allow it.) Of course the only way to verify what firmware is on the SSD is with a program when the SSD is connected to a PC. The Intel SSD Toolbox can do that.
Firmware updates on Intel SSDs have evolved from the usual boot disk update method, to the firmware update option in the SSD Toolbox. The boot disk tool is still available from the Intel Download page. The Release Notes for the tool lists all the firmware changes that occurred over time for various Intel SSDs, which you can read here:
The X-25M 80GB, G2 series (32nm NAND) SSDs had a few very early, short lived firmware versions, but I've never seen one that had an earlier version than the 2CV102HD (or 02HD) firmware, the version just before 2CV102M3 (02M3.) I have four of these SSDs, and all came with the 02HD firmware. Frankly, they all worked perfectly with that firmware, IMO the 02M3 version is not a required update unless you experience the issues it is intended to fix, which I never had.
If the Intel SSD Toolbox software recognizes that SSD on a PC, and does not "reject" it for some reason (ie, it won't perform some operations on non-Intel SSDs) then you should be able to update the firmware from there. This assumes you are using it on an Intel CPU/chipset PC. The SSD Toolbox:
You could use the boot disk tool on that SSD, which can be found here:
I've updated my 80GB G2's with both methods, and it always worked fine, and did not ruin the data on the SSDs. The ultimate and easy test for this SSD is to try it with the SSD Toolbox software and see what happens. BTW, the G2 SSDs are great products, mine all still work perfectly, if not at the speeds the latest SSDs do.