Dropbear before 2017.75 might allow local users to read certain files as root, if the file has the authorizedkeys file format with a command= option. This occurs because ~/.ssh/authorizedkeys is read with root privileges and symlinks are followed.
{
"binaries": [
{
"binary_version": "2016.72-1",
"binary_name": "dropbear"
},
{
"binary_version": "2016.72-1",
"binary_name": "dropbear-bin"
},
{
"binary_version": "2016.72-1",
"binary_name": "dropbear-initramfs"
},
{
"binary_version": "2016.72-1",
"binary_name": "dropbear-run"
}
]
}