{"id":"CVE-2021-42911","aliases":["EUVD-2021-29866","GHSA-436r-9cvq-hjq5"],"status":"published","title":"A Format String vulnerability exists in DrayTek Vigor 2960 \u003c= 1.5.1.3, DrayTek Vigor 3900 \u003c= 1.5...","description":"A Format String vulnerability exists in DrayTek Vigor 2960 \u003c= 1.5.1.3, DrayTek Vigor 3900 \u003c= 1.5.1.3, and DrayTek Vigor 300B \u003c= 1.5.1.3 in the mainfunction.cgi file via a crafted HTTP message containing malformed QUERY STRING, which could let a remote malicious user execute arbitrary code.","severity":{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-11","score":0.03524,"percentile":0.8939,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-134"],"published":"2022-03-29T19:30:16Z","modified":"2026-06-17T04:10:15Z","products":[{"vendor":"draytek","product":"vigor2960_firmware"},{"vendor":"draytek","product":"vigor300b_firmware"},{"vendor":"draytek","product":"vigor3900_firmware"}],"references":[{"url":"https://gist.github.com/Cossack9989/e9c1c2d2e69b773ca4251acdd77f2835","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-42911"},{"url":"https://github.com/advisories/GHSA-436r-9cvq-hjq5"}],"sources":{"cve":[{"id":"CVE-2021-42911","description":"A Format String vulnerability exists in DrayTek Vigor 2960 \u003c= 1.5.1.3, DrayTek Vigor 3900 \u003c= 1.5.1.3, and DrayTek Vigor 300B \u003c= 1.5.1.3 in the mainfunction.cgi file via a crafted HTTP message containing malformed QUERY STRING, which could let a remote malicious user execute arbitrary code.","status":"published","published":"2022-03-29T19:30:16Z","modified":"2024-08-04T03:47:12.398Z","updated_at":"2026-11-02T14:32:58.739039Z"}],"euvd":[{"id":"EUVD-2021-29866","description":"A Format String vulnerability exists in DrayTek Vigor 2960 \u003c= 1.5.1.3, DrayTek Vigor 3900 \u003c= 1.5.1.3, and DrayTek Vigor 300B \u003c= 1.5.1.3 in the mainfunction.cgi file via a crafted HTTP message containing malformed QUERY STRING, which could let a remote malicious user execute arbitrary code.","status":"published","published":"2022-03-29T19:30:16Z","modified":"2024-08-04T03:47:12Z","updated_at":"2026-11-03T03:24:15.299027Z"}],"ghsa":[{"id":"GHSA-436r-9cvq-hjq5","title":"A Format String vulnerability exists in DrayTek Vigor 2960 \u003c= 1.5.1.3, DrayTek Vigor 3900 \u003c= 1.5...","description":"A Format String vulnerability exists in DrayTek Vigor 2960 \u003c= 1.5.1.3, DrayTek Vigor 3900 \u003c= 1.5.1.3, and DrayTek Vigor 300B \u003c= 1.5.1.3 in the mainfunction.cgi file via a crafted HTTP message containing malformed QUERY STRING, which could let a remote malicious user execute arbitrary code.","status":"published","published":"2022-03-30T00:00:13Z","modified":"2023-01-27T05:01:08Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-134"],"updated_at":"2026-11-02T14:41:49.563138Z"}],"nvd":[{"id":"CVE-2021-42911","description":"A Format String vulnerability exists in DrayTek Vigor 2960 \u003c= 1.5.1.3, DrayTek Vigor 3900 \u003c= 1.5.1.3, and DrayTek Vigor 300B \u003c= 1.5.1.3 in the mainfunction.cgi file via a crafted HTTP message containing malformed QUERY STRING, which could let a remote malicious user execute arbitrary code.","status":"published","published":"2022-03-29T20:15:07.69Z","modified":"2026-06-17T04:10:15.89Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"},{"version":"2.0","score":7.5,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:P","level":"high","assessor":"primary"}],"cwes":["CWE-134"],"updated_at":"2026-11-02T14:07:05.581807Z"}]}}