Password are stored in plaintext in nvram in the HTTPd server in all current versions (<= 3.0.0.4.380.7743) of Asus asuswrt.

An issue was discovered in AsusWRT before 3.0.0.4.384_10007. The do_vpnupload_post function in router/httpd/web.c in vpnupload.cgi provides functionality for setting NVRAM configuration values, which allows attackers to set the admin password and launch an SSH daemon (or enable infosvr command mode), and consequently obtain remote administrative access, via a crafted request. This is available to unauthenticated attackers in conjunction with CVE-2018-5999.

An issue was discovered in AsusWRT before 3.0.0.4.384_10007. In the handle_request function in router/httpd/httpd.c, processing of POST requests continues even if authentication fails.

Stack-based buffer overflow in the ej_update_variables function in router/httpd/web.c on ASUS routers (when using software from https://github.com/RMerl/asuswrt-merlin) allows web authenticated attackers to execute code via a request that updates a setting. In ej_update_variables, the length of the variable action_script is not checked, as long as it includes a "_wan_if" substring.

Stack buffer overflow in httpd in Asuswrt-Merlin firmware 380.67_0RT-AC5300 and earlier for ASUS devices and ASUS firmware for ASUS RT-AC5300, RT_AC1900P, RT-AC68U, RT-AC68P, RT-AC88U, RT-AC66U, RT-AC66U_B1, RT-AC58U, RT-AC56U, RT-AC55U, RT-AC52U, RT-AC51U, RT-N18U, RT-N66U, RT-N56U, RT-AC3200, RT-AC3100, RT_AC1200GU, RT_AC1200G, RT-AC1200, RT-AC53, RT-N12HP, RT-N12HP_B1, RT-N12D1, RT-N12+, RT_N12+_PRO, RT-N16, and RT-N300 devices allows remote attackers to execute arbitrary code on the router by sending a crafted http GET request packet that includes a long delete_offline_client parameter in the url.