I presume Dropbear, thus musl-based OpenWrt routers are also not affected? Not that Dropbear has been an example in that regard.
There is this write-up/fancy page from the person who found the vulnerability[0] (HN discussion[1], how I found this thread).
At the bottom of that it says dropbear is unaffected.
> on debian, ubuntu, fedora or anything else with glibc? going through pam? dropbear? openbsd? you're fine
[0] https://sshhole.com/
[1] https://news.ycombinator.com/item?id=50378228
Since after you posted, various people in the thread have reported dropbear is not affected
There is this write-up/fancy page from the person who found the vulnerability[0] (HN discussion[1], how I found this thread).
At the bottom of that it says dropbear is unaffected.
> on debian, ubuntu, fedora or anything else with glibc? going through pam? dropbear? openbsd? you're fine
[0] https://sshhole.com/
[1] https://news.ycombinator.com/item?id=50378228