A non-persistent XSS (cross-site scripting) vulnerability exists in eWON Flexy and Cosy (all firmware versions prior to 14.1s0).

published 2020-04-08 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-3081

cvss: 6.1; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.7%; EPSS 0.7% chance of exploitation in 30 days, percentile 52%
public exploits: 0; none known

A non-persistent XSS (cross-site scripting) vulnerability exists in eWON Flexy and Cosy (all firmware versions prior to 14.1s0). An attacker could send a specially crafted URL to initiate a password change for the device. The target must introduce the credentials to the gateway before the attack can be successful.

Patch / fix

fixed in 2

hms-networks ewon_flexy_firmware 14.1s0
hms-networks ewon_cosy_firmware 14.1s0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-20-098-03 updated 2020-04-07 cvss 6.1

HMS Networks eWON Flexy and Cosy

HMS Networks eWON Cosy < 14.1s0 HMS Networks eWON Flexy < 14.1s0
affected: mitigation “HMS Networks recommends users update to latest firmware, Version 14.1s0” ewon.biz

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

Exploit prediction

0.69% chance of exploitation in the next 30 days, higher than 52% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD	2.0	4.3	AV:N/AC:M/Au:N/C:N/I:P/A:N

Affected products

n/a eWON Flexy and Cosy

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

us-cert.gov /ics/advisories/icsa-20-098-03
third-party-advisory, us-government-resource

Sources

CVE List CVE-2020-10633
NVD CVE-2020-10633

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