Cosy+ devices running a firmware 21.x below 21.2s10 or a firmware 22.x below 22.1s3 use a unique key to encrypt the configuration parameter…

published 2024-08-02 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-31599

cvss: 6.6; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.5%; EPSS 0.5% chance of exploitation in 30 days, percentile 44%
public exploits: 0; none known

Cosy+ devices running a firmware 21.x below 21.2s10 or a firmware 22.x below 22.1s3 use a unique key to encrypt the configuration parameters. This is fixed in version 21.2s10 and 22.1s3, the key is now unique per device.

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 y ago (2024-08-07)

Exploit prediction

0.52% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

blog.syss.com https://blog.syss.com/posts/hacking-a-secure-industrial-remote-access-gateway/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	6.6	CVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD	3.1	6.6	CVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CNA	3.1	6.6	CVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Classification

Weakness

CWE-798 Use of Hard-coded Credentials

References

blog.syss.com /posts/hacking-a-secure-industrial-remote-access-gateway/
exploit, third-party-advisory
hms-networks.com /cyber-security
vendor-advisory
hmsnetworks.blob.core.windows.net /nlw/docs/default-source/products/cybersecurity/security-advisory/hms-security-advisory-2024-07-29-001--ewon-s
vendor-advisory
ewon.biz /products/cosy/ewon-cosy-wifi
product
seclists.org /fulldisclosure/2024/Aug/22

Sources

CVE List CVE-2024-33895
NVD CVE-2024-33895

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