Dan Goodin writes via Ars Technica: For almost three years, OpenWRT — the open source operating system that powers home routers and other types of embedded systems — has been vulnerable to remote code-execution attacks because updates were delivered over an unencrypted channel and digital signature verifications are easy to bypass, a researcher said. Security researcher Guido Vranken, however, recently found that updates and installation files were delivered over unencrypted HTTPs connections, which are open to attacks that allow adversaries to completely replace legitimate updates with malicious ones. The researcher also found that it was trivial for attackers with moderate experience to bypass digital-signature checks that verify a downloaded update as the legitimate one offered by OpenWTR maintainers. The combination of those two lapses makes it possible to send a malicious update that vulnerable devices will automatically install. […] The researcher said that OpenWRT maintainers have released a stopgap solution that partially mitigates the risk the bug poses. The mitigation requires new installations to be “set out from a well-formed list that would not sidestep the hash verification. However, this is not an adequate long-term solution because an attacker can simply provide an older package list that was signed by the OpenWRT maintainers.” From there, attackers can use the same exploits they would use on devices that haven’t received the mitigation. OpenWRT maintainers didn’t immediately respond to questions asking why installation and update files are delivered over HTTP and when a longer-term fix might be available. In the meantime, OpenWRT users should install either version 18.06.7 or 19.07.1, both of which were released in February. These updates provide the stopgap mitigation. Read more of this story at Slashdot.