Cisco Unified Contact Center Express: Missing Authentication for Critical Functionality
CVE-2025-20358 is a critical-severity missing authentication for critical functionality 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 0.92% chance of exploitation within 30 days, higher than 61% 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 NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.4 | Critical | CNA (cisco.com) |
| CVSS 3.1 | 9.8 | Critical | NVD |
Official description
A vulnerability in the Contact Center Express (CCX) Editor application of Cisco Unified CCX could allow an unauthenticated, remote attacker to bypass authentication and obtain administrative permissions pertaining to script creation and execution. This vulnerability is due to improper authentication mechanisms in the communication between the CCX Editor and an affected Unified CCX server. An attacker could exploit this vulnerability by redirecting the authentication flow to a malicious server and tricking the CCX Editor into believing the authentication was successful. A successful exploit could allow the attacker to create and execute arbitrary scripts on the underlying operating system of an affected Unified CCX server, as an internal non-root user account.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Missing Authentication for Critical Functionality
The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
How developers prevent this class of flaw
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator.
- When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to require strong authentication for users who should be allowed to access the data.
More Missing Authentication for Critical Functionality vulnerabilities (CWE-306)
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 Missing Authentication for Critical Functionality vulnerabilities
- 10.0 Critical severity
- 9.3 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.1 High severity
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