Totolink A7100RU CGI cstecgi.cgi UploadFirmwareFile os command injection

published 2026-04-13 6 mo ago modified 2026-10-26 13 d ago also EUVD-2026-21766

cvss: 9.8; version 3.1, 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

A vulnerability was found in Totolink A7100RU 7.4cu.2313_b20191024. This impacts the function UploadFirmwareFile of the file /cgi-bin/cstecgi.cgi of the component CGI Handler. Performing a manipulation of the argument FileName results in os command injection. The attack may be initiated remotely. The exploit has been made public and could be used.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: total
Assessed: 6 mo ago (2026-04-13)

Exploit prediction

2.20% chance of exploitation in the next 30 days, higher than 82% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/Litengzheng/vuldb_new/blob/main/A7100RU/vul_193/README.md 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/E:P
CNA	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R
CNA	3.0	9.8	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R
CNA	2.0	10.0	AV:N/AC:L/Au:N/C:C/I:C/A:C/E:POC/RL:ND/RC:UR
CNA	4.0	8.9	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:P/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
CNA	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA	2.0	10.0	AV:N/AC:L/Au:N/C:C/I:C/A:C

Affected products

Totolink A7100RU

Classification

Weakness

CWE-78 Improper Neutralization of Special Elements used in an OS Command
CWE-77 Improper Neutralization of Special Elements used in a Command

References

github.com /Litengzheng/vuldb_new/blob/main/A7100RU/vul_193/README.md
exploit
vuldb.com /vuln/357004
vdb-entry, technical-description
vuldb.com /vuln/357004/cti
signature, permissions-required
vuldb.com /submit/792987
third-party-advisory
totolink.net /
product

Sources

CVE List CVE-2026-6140
NVD CVE-2026-6140

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