Title: FIBerHome AN5506-04-FA / HG6245D Routers Remote Stack Overflow Severity: HIGH Date: November 12, 2025 Affecting: - AN5506-04-FA firmware versions <= RP2631 - HG6245D firmware versions < RP2602 - Other router models and versions are likely affected CVE: CVE-2021-4464 CWE: CWE-121 Stack-based Buffer Overflow CVSS: 9.3 CVSS V4 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 References: - Researcher Disclosure - Researcher Advisory Credit: Pierre Barre 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. A cookie longer than 511 bytes leads to a crash or potential control of execution flow.