Complex sentence: Netgear, along with other companies with products manufactured by SerComm that were affected by the aforementioned backdoor issued firmware updates for some of the affected products, but it was shortly found that the updates merely hid the backdoor but did not remove it.
Split into simpler sentences: Netgear, along with other companies with products manufactured by SerComm that were affected by the aforementioned backdoor, issued firmware updates for some affected products. However, it was shortly found that the updates merely hid the backdoor but did not remove it.