Cisco Unified Contact Center Express: Unrestricted Upload of File with Dangerous Type
CVE-2025-20354 is a critical-severity unrestricted upload of file with dangerous type vulnerability in Cisco Unified Contact Center Express from Cisco, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Cisco Unified Contact Center Express versions: 10.5(1)SU1; 10.6(1); 11.6(1), and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.87% chance of exploitation within 30 days, higher than 59% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Unified Contact Center Express to 12.5\(1\)_su03_es07 or a later version.
- Read the advisory on sec.cloudapps.cisco.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Cisco | Cisco Unified Contact Center Express | 10.5(1)SU1; 10.6(1); 11.6(1); 10.6(1)SU1; 10.6(1)SU3; 11.6(2); 12.0(1); 11.0(1)SU1; and 32 more ranges | Not stated |
| Cisco | Unified Contact Center Express | before 12.5\(1\)_su03_es07; 15.0 | 12.5\(1\)_su03_es07 |
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
- NoneNo account or login is needed.
- 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:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (cisco.com).
Official description
A vulnerability in the Java Remote Method Invocation (RMI) process of Cisco Unified CCX could allow an unauthenticated, remote attacker to upload arbitrary files and execute arbitrary commands with root permissions on an affected system. This vulnerability is due to improper authentication mechanisms that are associated to specific Cisco Unified CCX features. An attacker could exploit this vulnerability by uploading a crafted file to an affected system through the Java RMI process. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system and elevate privileges to root.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Unrestricted Upload of File with Dangerous Type
The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.
How developers prevent this class of flaw
- Generate a new, unique filename for an uploaded file instead of using the user-supplied filename, so that no external input is used at all.
- When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
- Consider storing the uploaded files outside of the web document root entirely. Then, use other mechanisms to deliver the files dynamically.
More Unrestricted Upload of File with Dangerous Type vulnerabilities (CWE-434)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in Cisco Unified Contact Center Express
- 7.2 High severity
- 7.2 High severity
- 9.8 Critical severity
- 8.8 High severity
- 7.2 High severity
- 7.8 High severity
Recent Unrestricted Upload of File with Dangerous Type vulnerabilities
- 7.2 High severity
- 9.9 Critical severity
- 7.2 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
Spotted an error? Tell us.