{"cve":"CVE-2021-27257","nvd":{"published":"2021-03-05T20:15:12.660","modified":"2026-06-17T03:44:33.920","status":"Modified","description":"This vulnerability allows network-adjacent attackers to compromise the integrity of downloaded information on affected installations of NETGEAR R7800 firmware version 1.0.2.76. Authentication is not required to exploit this vulnerability. The specific flaw exists within the downloading of files via FTP. The issue results from the lack of proper validation of the certificate presented by the server. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of root. Was ZDI-CAN-12362.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","score":6.5},"cwes":["CWE-295"],"references":["https://kb.netgear.com/000062883/Security-Advisory-for-Multiple-Vulnerabilities-on-Some-Routers-Satellites-and-Extenders","https://www.zerodayinitiative.com/advisories/ZDI-21-264/","https://kb.netgear.com/000062883/Security-Advisory-for-Multiple-Vulnerabilities-on-Some-Routers-Satellites-and-Extenders","https://www.zerodayinitiative.com/advisories/ZDI-21-264/"],"products":["netgear:br200_firmware","netgear:br500_firmware","netgear:d7800_firmware","netgear:ex6100v2_firmware","netgear:ex6150v2_firmware","netgear:ex6250_firmware","netgear:ex6400_firmware","netgear:ex6400v2_firmware","netgear:ex6410_firmware","netgear:ex6420_firmware","netgear:ex7300_firmware","netgear:ex7300v2_firmware","netgear:ex7320_firmware","netgear:ex7700_firmware","netgear:ex8000_firmware","netgear:lbr20_firmware","netgear:r7800_firmware","netgear:r8900_firmware","netgear:r9000_firmware","netgear:rbk12_firmware","netgear:rbk13_firmware","netgear:rbk14_firmware","netgear:rbk15_firmware","netgear:rbk20_firmware","netgear:rbk23_firmware","netgear:rbk40_firmware","netgear:rbk43_firmware","netgear:rbk43s_firmware","netgear:rbk44_firmware","netgear:rbk50_firmware","netgear:rbk53_firmware","netgear:rbr10_firmware","netgear:rbr20_firmware","netgear:rbr40_firmware","netgear:rbr50_firmware","netgear:rbs10_firmware","netgear:rbs20_firmware","netgear:rbs40_firmware","netgear:rbs50_firmware","netgear:rbs50y_firmware","netgear:xr450_firmware","netgear:xr500_firmware","netgear:xr700_firmware"],"source":"nvd","synced_at":"2026-10-19T21:15:50.279857260+00:00"},"epss":{"cve":"CVE-2021-27257","score":0.00323,"percentile":0.25344,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}