Zyxel GS1900 Patch Fails to Block Zero-Day Exploit Allowing Root Command Execution

Zyxel GS1900 network switches that received an earlier fix for an actively exploited flaw remain vulnerable to the same exploit, allowing unauthenticated root command execution via the web management interface. Researchers at Binarly found the patch incomplete. Zyxel has released new firmware for 10 GS1900 models to close the hole, but the earlier fix (version 2.90) failed to block the attack.