CVE-2021-4464

CRITICAL EPSS 75.4%
Published Nov 12, 20257mo ago · Modified Jun 17, 20261w ago
9.3 CVSS 4.0
Critical
Find Similar
Published Nov 12, 2025 7mo ago
Last Modified Jun 17, 2026 1w ago

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.

CVSS Details

Base Score
9.3
Exploitability
—
Impact
—
Vector string
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
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
75.4% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-121

References 3

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

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.