ewon_cosy: Improper Privilege Management
CVE-2024-33894 is a high-severity improper privilege management vulnerability in ewon_cosy from HMS Networks, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists versions 21.2s10, 22.1s3 as the first without the flaw, so updating ewon_cosy to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.85% chance of exploitation within 30 days, higher than 59% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update ewon_cosy to 21.2s10 or 22.1s3, whichever matches your release line, or a later version.
- Update Ewon Cosy+ Firmware to 21.2s10 or 22.1s3, whichever matches your release line, or a later version.
- Read the advisory on hmsnetworks.blob.core.windows.net for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Hms-networks | ewon_cosy | 21.x up to, but not including, 21.2s10; 22.x up to, but not including, 22.1s3 | 21.2s10, 22.1s3 |
| Hms-networks | Ewon Cosy+ Firmware | 21.0s0 up to, but not including, 21.2s10; 22.0s0 up to, but not including, 22.1s3 | 21.2s10, 22.1s3 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CISA (ADP).
Official description
Insecure Permission vulnerability in Cosy+ devices running a firmware 21.x below 21.2s10 or a firmware 22.x below 22.1s3 are executing several processes with elevated privileges.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Privilege Management
The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.
How developers prevent this class of flaw
- Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
- Follow the principle of least privilege when assigning access rights to entities in a software system.
- Consider following the principle of separation of privilege. Require multiple conditions to be met before permitting access to a system resource.
More Improper Privilege Management vulnerabilities (CWE-269)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Technical write-ups (may include proof of concept)
- blog.syss.com/posts/hacking-a-secure-industrial-remote-access-gateway/Exploit, Third Party Advisory
- seclists.org/fulldisclosure/2024/Aug/23Exploit, Mailing List
Other references
Recent Improper Privilege Management vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 9.8 Critical severity
- 8.0 High severity
- 7.8 High severity
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