CVE-2021-4464 json
FIberHome AN5506-04-FA / HG6245D Routers Remote Stack Overflow
published 2025-11-12 11 mo ago modified 2026-06-17 4 mo ago also EUVD-2021-34714
- cvss
- 9.3
- version 4.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 2.2%
- EPSS 2.2% chance of exploitation in 30 days, percentile 82%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- FiberHome HG6245D RP2602
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- total
- Assessed
- 11 mo ago
Exploit prediction
2.18% chance of exploitation in the next 30 days, higher than 82% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- pierrekim.github.io https://pierrekim.github.io/blog/2021-01-12-fiberhome-ont-0day-vulnerabilities.html#misc-remote-stack-overflow-an5506 referenced PoC, tagged "exploit" by a source, unverified
- pierrekim.github.io https://pierrekim.github.io/advisories/2021-fiberhome-0x00-ont.txt referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 9.3 | 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 |
| CNA | 4.0 | 9.3 | 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 |
Affected products
- FiberHome AN5506-04-FA
- FiberHome HG6245D
Classification
- Weakness
-
- CWE-121 Stack-based Buffer Overflow
References
-
pierrekim.github.io
/blog/2021-01-12-fiberhome-ont-0day-vulnerabilities.html#misc-remote-stack-overflow-an5506
technical-description, exploit
-
pierrekim.github.io
/advisories/2021-fiberhome-0x00-ont.txt
technical-description, exploit
-
vulncheck.com
/advisories/fiberhome-routers-remote-stack-overflow
third-party-advisory
Sources
- CVE List CVE-2021-4464
- NVD CVE-2021-4464
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