{"id":"CVE-2018-5721","aliases":["EUVD-2018-17490","GHSA-8hc5-mr39-qw3v"],"status":"published","title":"Stack-based buffer overflow in the ej_update_variables function in router/httpd/web.c on ASUS...","description":"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.","severity":{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-08","score":0.01938,"percentile":0.80229,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-787"],"published":"2018-01-17T06:00:00Z","modified":"2026-06-17T02:00:39Z","products":[{"vendor":"asuswrt-merlin","product":"asuswrt-merlin"}],"references":[{"url":"http://www.w0lfzhang.com/2018/01/17/ASUS-router-stack-overflow-in-http-server/","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2018-5721"},{"url":"https://github.com/advisories/GHSA-8hc5-mr39-qw3v"}],"sources":{"cve":[{"id":"CVE-2018-5721","description":"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.","status":"published","published":"2018-01-17T06:00:00Z","modified":"2024-08-05T05:40:51.215Z","updated_at":"2026-11-02T14:35:01.28843Z"}],"euvd":[{"id":"EUVD-2018-17490","description":"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.","status":"published","published":"2018-01-17T06:00:00Z","modified":"2024-08-05T05:40:51Z","updated_at":"2026-11-03T02:40:10.116776Z"}],"ghsa":[{"id":"GHSA-8hc5-mr39-qw3v","title":"Stack-based buffer overflow in the ej_update_variables function in router/httpd/web.c on ASUS...","description":"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.","status":"published","published":"2022-05-13T01:20:20Z","modified":"2023-02-01T05:06:09Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:50:19.146831Z"}],"nvd":[{"id":"CVE-2018-5721","description":"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.","status":"published","published":"2018-01-17T06:29:00.277Z","modified":"2026-06-17T02:00:39.37Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":6.5,"vector":"AV:N/AC:L/Au:S/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:04:22.309028Z"}]}}