WSO2 API Manager: Improper Neutralization of Special Elements in Output Used by a Downstream Component
CVE-2025-8154 is a high-severity improper neutralization of special elements in output used by a downstream component vulnerability in WSO2 API Manager from WSO2, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 4.1.0.218, 4.2.0.164, 4.3.0.74 as the first without the flaw, so updating WSO2 API Manager to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.19% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update WSO2 API Manager to 4.1.0.218 or 4.2.0.164 or 4.3.0.74 or 4.4.0.38, whichever matches your release line, or a later version.
- Update WSO2 Universal Gateway to 4.5.0.19 or a later version.
- Update WSO2 Traffic Manager to 4.5.0.19 or a later version.
- Read the advisory on security.docs.wso2.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 |
|---|---|---|---|
| WSO2 | WSO2 API Manager | 4.1.0 up to, but not including, 4.1.0.218; 4.2.0 up to, but not including, 4.2.0.164; 4.3.0 up to, but not including, 4.3.0.74; 4.4.0 up to, but not including, 4.4.0.38; 4.5.0 up to, but not including, 4.5.0.20 | 4.1.0.218, 4.2.0.164, 4.3.0.74, 4.4.0.38, 4.5.0.20 |
| WSO2 | WSO2 Universal Gateway | 4.5.0 up to, but not including, 4.5.0.19 | 4.5.0.19 |
| WSO2 | WSO2 Traffic Manager | 4.5.0 up to, but not including, 4.5.0.19 | 4.5.0.19 |
| WSO2 | WSO2 API Control Plane | 4.5.0 up to, but not including, 4.5.0.21 | 4.5.0.21 |
| WSO2 | WSO2 Carbon API Gateway | 9.20.74 up to, but not including, 9.20.74.374; 9.28.116 up to, but not including, 9.28.116.363; 9.29.120 up to, but not including, 9.29.120.181; 9.30.67 up to, but not including, 9.30.67.104; 9.31.86 up to, but not including, 9.31.86.64 | 9.20.74.374, 9.28.116.363, 9.29.120.181, 9.30.67.104, 9.31.86.64 |
| WSO2 | WSO2 Carbon API Management Implementation | 9.20.74 up to, but not including, 9.20.74.374; 9.28.116 up to, but not including, 9.28.116.363; 9.29.120 up to, but not including, 9.29.120.181; 9.30.67 up to, but not including, 9.30.67.104; 9.31.86 up to, but not including, 9.31.86.64 | 9.20.74.374, 9.28.116.363, 9.29.120.181, 9.30.67.104, 9.31.86.64 |
| WSO2 | API Control Plane | 4.5.0 up to, but not including, 4.5.0.21 | 4.5.0.21 |
| WSO2 | API Manager | 4.1.0 up to, but not including, 4.1.0.218; 4.2.0 up to, but not including, 4.2.0.164; 4.3.0 up to, but not including, 4.3.0.74; 4.4.0 up to, but not including, 4.4.0.38; 4.5.0 up to, but not including, 4.5.0.20 | 4.1.0.218, 4.2.0.164, 4.3.0.74, 4.4.0.38, 4.5.0.20 |
| WSO2 | Traffic Manager | 4.5.0 up to, but not including, 4.5.0.19 | 4.5.0.19 |
| WSO2 | Universal Gateway | 4.5.0 up to, but not including, 4.5.0.19 | 4.5.0.19 |
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
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 5.3 | Medium | CNA |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
In Webhook API invocations, the component accepts user-supplied input for HTTP request headers without sufficient validation or sanitization, allowing these headers to be injected into HTTP responses. By exploiting this vulnerability, a malicious actor can inject or overwrite arbitrary HTTP response headers. This can lead to various adverse effects, including the manipulation of browser caching, alteration of security-related headers, and the injection of sensitive information such as cookie values, potentially enabling session hijacking or other malicious activities.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements in Output Used by a Downstream Component
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
How developers prevent this class of flaw
- Programming languages and supporting technologies might be chosen which are not subject to these issues.
- Utilize an appropriate mix of allowlist and denylist parsing to filter control-plane syntax from all input.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in WSO2 API Manager
- 9.8 Critical severity
- 8.7 High severity
- 9.4 Critical severity
- 8.3 High severity
- 9.1 Critical severity
- 8.4 High severity
Recent Improper Neutralization of Special Elements in Output Used by a Downstream Component vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 7.2 High severity
- 7.3 High severity
- 7.3 High severity
- 7.3 High severity
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