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.
References (3)
Core 3
Core References
Various Sources technical-description
exploit
https://pierrekim.github.io/blog/2021-01-12-fiberhome-ont-0day-vulnerabilities.html#misc-remote-stack-overflow-an5506
Various Sources technical-description
exploit
https://pierrekim.github.io/advisories/2021-fiberhome-0x00-ont.txt
Third Party Advisory third-party-advisory
https://www.vulncheck.com/advisories/fiberhome-routers-remote-stack-overflow
Scores
CVSS v4
9.3
EPSS
0.0178
EPSS Percentile
75.4%
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
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
total
Details
CWE
CWE-121
Status
published
Products (2)
FiberHome/AN5506-04-FA
< RP2631
FiberHome/HG6245D
< RP2602
Published
Nov 12, 2025
Tracked Since
Feb 18, 2026