Critical 9.3Published Nov 12, 2025

CVE-2021-4464FIberHome AN5506-04-FA / HG6245D Routers Remote Stack Overflow

Updated under an hour ago (Oct 27, 2026, 8:10 AM ET)

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It affects FiberHome AN5506-04-FA and 1 other product. Add what you run to find out whether that includes you.

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Every CVE for FiberHome AN5506-04-FA

Exploited in the last 30 days

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.

CVSS: 9.3 CRITICAL (v4.0, CNA)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
Weakness (CWE): CWE-121
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: VulnCheck
NVD analysis: Deferred
Record last updated: Nov 21, 2025
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

FiberHome AN5506-04-FA fiberhome:an5506_04_fa (from the name)	through RP2631	CNA record
FiberHome HG6245D fiberhome:hg6245d (from the name)	before RP2602	CNA record

References

References

https://pierrekim.github.io/blog/2021-01-12-fiberhome-ont-0day-vulnerabilities.html#misc-remote-stack-overflow-an5506	technical-description, exploit
https://pierrekim.github.io/advisories/2021-fiberhome-0x00-ont.txt	technical-description, exploit
https://www.vulncheck.com/advisories/fiberhome-routers-remote-stack-overflow	third-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.