PT-2025-46729 · Fiberhome · Hg6245D+1

Pierre Barre · Published 2025-11-12 · Updated 2025-11-13 · CVE-2021-4464

Positive Technologies (AI Summary)

CVSS v4.0

9.3

Critical

Base vector

AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Name of the Vulnerable Software and Affected Versions FiberHome AN5506-04-FA firmware versions up to and including RP2631 FiberHome HG6245D versions prior to RP2602

Description The HTTP service ('webs') does not properly limit the size of Cookie header values, resulting in a stack-based buffer overflow. Processing a cookie exceeding 511 bytes causes an overrun of a stack buffer, potentially leading to a crash or control of execution.

Recommendations Update FiberHome AN5506-04-FA firmware to a version later than RP2631. Update FiberHome HG6245D firmware to a version RP2602 or later.

Exploit

Fix

RCE

Stack Overflow

Weakness Enumeration

CWE-121

Related Identifiers

CVE-2021-4464

Affected Products

An5506-04-Fa

Hg6245D

References · 6

• 🔥 https://pierrekim.github.io/blog/2021-01-12-fiberhome-ont-0day-vulnerabilities.html#misc-remote-stack-overflow-an5506 · Exploit
• 🔥 https://pierrekim.github.io/advisories/2021-fiberhome-0x00-ont.txt · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2021-4464 · Security Note
• https://vulncheck.com/advisories/fiberhome-routers-remote-stack-overflow · Note
• https://twitter.com/CVEnew/status/1988820412965556439 · Twitter Post
• https://twitter.com/0dayPublishing/status/1988734755714605170 · Twitter Post