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.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00651.

Exploitation none

Automatable yes

Technical Impact total

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
FiberHome AN5506-04-FA unaffected
Version Status Constraints
0 affected
≤ RP2631
FiberHome HG6245D unaffected
Version Status Constraints
0 affected
< RP2602

No data.

No data.

Vendor Product Confidence Versions
Fiberhome An5506-04-fa — —
Fiberhome Hg6245d — —

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Subscriptions

Vendors Products
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Tracking

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Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://pierrekim.github.io/advisories/2021-fiberhome-0x00-ont.txt cve-icon cve-icon
https://pierrekim.github.io/blog/2021-01-12-fiberhome-ont-0day-vulnerabilities.html#misc-remote-stack-overflow-an5506 cve-icon cve-icon
https://www.vulncheck.com/advisories/fiberhome-routers-remote-stack-overflow cve-icon cve-icon
History

Fri, 21 Nov 2025 15:45:00 +0000

Type Values Removed Values Added
First Time appeared Fiberhome an5506-04-fa Firmware
Fiberhome hg6245d Firmware
CPEs cpe:2.3:o:fiberhome:an5506-04-fa_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:fiberhome:hg6245d_firmware:*:*:*:*:*:*:*:*
Vendors & Products Fiberhome an5506-04-fa Firmware
Fiberhome hg6245d Firmware

Thu, 13 Nov 2025 15:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Thu, 13 Nov 2025 10:00:00 +0000

Type Values Removed Values Added
First Time appeared Fiberhome
Fiberhome an5506-04-fa
Fiberhome hg6245d
Vendors & Products Fiberhome
Fiberhome an5506-04-fa
Fiberhome hg6245d

Wed, 12 Nov 2025 22:15:00 +0000

Type Values Removed Values Added
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.
Title FIberHome AN5506-04-FA / HG6245D Routers Remote Stack Overflow
Weaknesses CWE-121
References
Metrics cvssV4_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'}
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2025-11-21T15:36:02.534Z

Reserved: 2025-11-12T21:24:45.845Z

Link: CVE-2021-4464

cve-icon Vulnrichment

Updated: 2025-11-13T14:30:34.032Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-11-12T22:15:42.027

Modified: 2025-11-14T16:42:30.503

Link: CVE-2021-4464

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2025-11-13T09:52:14Z

Weaknesses