Linksys FGW3000-AH/FGW3000-HK HTTP POST Request sysconf.cgi sub_4153FC command injection

published 2025-05-20 17 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-15959

cvss: 6.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 6.9%; EPSS 6.9% chance of exploitation in 30 days, percentile 94%
public exploits: 0; none known

A vulnerability was found in Linksys FGW3000-AH and FGW3000-HK up to 1.0.17.000000 and classified as critical. Affected by this issue is the function sub_4153FC of the file /cgi-bin/sysconf.cgi of the component HTTP POST Request Handler. The manipulation of the argument supplicant_rnd_id_en leads to command injection. The attack may be launched remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 17 mo ago (2025-05-21)

Exploit prediction

6.87% chance of exploitation in the next 30 days, higher than 94% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/CH13hh/tmp_store_cc/blob/main/FGW3000/1.md referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	5.3	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N
CNA	3.1	6.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
CNA	3.0	6.3	CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
CNA	2.0	6.5	AV:N/AC:L/Au:S/C:P/I:P/A:P
CNA	4.0	5.3	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/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
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Linksys FGW3000-AH
Linksys FGW3000-HK

Classification

Weakness

CWE-77 Improper Neutralization of Special Elements used in a Command
CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component

References

github.com /CH13hh/tmp_store_cc/blob/main/FGW3000/1.md
broken-link, exploit
vuldb.com /?id.309650
vdb-entry, technical-description, third-party-advisory
vuldb.com /?ctiid.309650
signature, permissions-required, vdb-entry
vuldb.com /?submit.565909
third-party-advisory, vdb-entry
linksys.com /
product

Sources

CVE List CVE-2025-4999
NVD CVE-2025-4999

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary