{"id":"CVE-2021-4464","aliases":["EUVD-2021-34714","GHSA-9m65-3xwh-873p"],"status":"published","title":"FIberHome AN5506-04-FA / HG6245D Routers Remote Stack Overflow","description":"FiberHome AN5506-04-FA firmware versions up to and including RP2631 and HG6245D prior to RP2602 contain a stack-based buffer overflow, as the HTTP service ('webs') fails to enforce maximum lengths for Cookie header values. When a cookie longer than 511 bytes is processed, a stack buffer is overrun, leading to a crash or potential control of execution flow.","severity":{"version":"4.0","score":9.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.02177,"percentile":0.82482,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-121"],"published":"2025-11-12T22:09:20Z","modified":"2026-06-17T04:19:48Z","products":[{"vendor":"fiberhome","product":"an5506-04-fa"},{"vendor":"fiberhome","product":"hg6245d"}],"references":[{"url":"https://pierrekim.github.io/blog/2021-01-12-fiberhome-ont-0day-vulnerabilities.html#misc-remote-stack-overflow-an5506","tags":["technical-description","exploit"]},{"url":"https://pierrekim.github.io/advisories/2021-fiberhome-0x00-ont.txt","tags":["technical-description","exploit"]},{"url":"https://www.vulncheck.com/advisories/fiberhome-routers-remote-stack-overflow","tags":["third-party-advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-4464"},{"url":"https://github.com/advisories/GHSA-9m65-3xwh-873p"}],"sources":{"cve":[{"id":"CVE-2021-4464","title":"FIberHome AN5506-04-FA / HG6245D Routers Remote Stack Overflow","description":"FiberHome AN5506-04-FA firmware versions up to and including RP2631 and HG6245D prior to RP2602 contain a stack-based buffer overflow, as the HTTP service ('webs') fails to enforce maximum lengths for Cookie header values. When a cookie longer than 511 bytes is processed, a stack buffer is overrun, leading to a crash or potential control of execution flow.","status":"published","published":"2025-11-12T22:09:20.835Z","modified":"2025-11-21T15:36:02.534Z","cvss":[{"version":"4.0","score":9.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"critical","assessor":"cna"}],"cwes":["CWE-121"],"updated_at":"2026-11-02T14:33:08.045407Z"}],"euvd":[{"id":"EUVD-2021-34714","description":"FiberHome AN5506-04-FA firmware versions up to and including RP2631 and HG6245D prior to RP2602 contain a stack-based buffer overflow, as the HTTP service ('webs') fails to enforce maximum lengths for Cookie header values. When a cookie longer than 511 bytes is processed, a stack buffer is overrun, leading to a crash or potential control of execution flow.","status":"published","published":"2025-11-12T22:09:20Z","modified":"2025-11-21T15:36:02Z","cvss":[{"version":"4.0","score":9.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"critical"}],"updated_at":"2026-11-02T19:49:13.665045Z"}],"ghsa":[{"id":"GHSA-9m65-3xwh-873p","title":"FiberHome AN5506-04-FA firmware versions up to and including RP2631 and HG6245D prior to RP2602...","description":"FiberHome AN5506-04-FA firmware versions up to and including RP2631 and HG6245D prior to RP2602 contain a stack-based buffer overflow, as the HTTP service ('webs') fails to enforce maximum lengths for Cookie header values. When a cookie longer than 511 bytes is processed, a stack buffer is overrun, leading to a crash or potential control of execution flow.","status":"published","published":"2025-11-13T00:30:17Z","modified":"2025-11-13T00:30:24Z","cvss":[{"version":"4.0","score":9.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"critical"}],"cwes":["CWE-121"],"updated_at":"2026-11-02T15:04:46.9648Z"}],"nvd":[{"id":"CVE-2021-4464","description":"FiberHome AN5506-04-FA firmware versions up to and including RP2631 and HG6245D prior to RP2602 contain a stack-based buffer overflow, as the HTTP service ('webs') fails to enforce maximum lengths for Cookie header values. When a cookie longer than 511 bytes is processed, a stack buffer is overrun, leading to a crash or potential control of execution flow.","status":"published","published":"2025-11-12T22:15:42.027Z","modified":"2026-06-17T04:19:48.85Z","cvss":[{"version":"4.0","score":9.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"critical","assessor":"secondary"}],"cwes":["CWE-121"],"updated_at":"2026-11-02T14:07:09.005706Z"}]}}