Summary
Apache Camel's AS2 component contains a server-side request forgery vulnerability in asynchronous Message Disposition Notification delivery. A remote AS2 partner may influence the destination contacted by the Camel receiver, potentially reaching internal services and exposing credentials configured for receipt delivery.
Apache Camel's AS2 component contains a server-side request forgery vulnerability in asynchronous Message Disposition Notification delivery. A remote AS2 partner may influence the destination contacted by the Camel receiver, potentially reaching internal services and exposing credentials configured for receipt delivery.
Affected context
The issue occurs in Apache Camel deployments using the AS2 component to generate asynchronous Message Disposition Notifications. It becomes risky when the destination supplied in an inbound AS2 message is accepted without being constrained to deployment-approved partner endpoints, allowing outbound connections to attacker-selected hosts.
The issue occurs in Apache Camel deployments using the AS2 component to generate asynchronous Message Disposition Notifications. It becomes risky when the destination supplied in an inbound AS2 message is accepted without being constrained to deployment-approved partner endpoints, allowing outbound connections to attacker-selected hosts.
Exploit preconditions
- Attack surface: The AS2 message-receiving endpoint and asynchronous MDN delivery workflow
- Required access: Ability to act as or control an AS2 communication partner that can submit messages
- Trigger point: Processing an inbound message that requests an asynchronous MDN
- Why exploitation is possible: The receiver uses a sender-supplied destination without sufficiently restricting it to trusted, deployment-configured endpoints
- Attack surface: The AS2 message-receiving endpoint and asynchronous MDN delivery workflow
- Required access: Ability to act as or control an AS2 communication partner that can submit messages
- Trigger point: Processing an inbound message that requests an asynchronous MDN
- Why exploitation is possible: The receiver uses a sender-supplied destination without sufficiently restricting it to trusted, deployment-configured endpoints
Why this happens
The vulnerability results from trusting an externally supplied URI as the destination for a server-initiated outbound request. This behavior maps to CWE-918: Server-Side Request Forgery, because the application allows a remote party to influence where the server connects. The risk is increased when the outbound request includes credentials or can reach hosts accessible only from the deployment network.
The vulnerability results from trusting an externally supplied URI as the destination for a server-initiated outbound request. This behavior maps to CWE-918: Server-Side Request Forgery, because the application allows a remote party to influence where the server connects. The risk is increased when the outbound request includes credentials or can reach hosts accessible only from the deployment network.
Potential impact
- The Camel instance may connect to internal or otherwise restricted network services
- Cloud metadata or administrative endpoints could be probed where network access permits
- Credentials configured for MDN delivery could be disclosed to an attacker-controlled destination
- Internal services may receive unexpected requests from a trusted network location
- The deployment's network segmentation and trust boundaries could be weakened
- The Camel instance may connect to internal or otherwise restricted network services
- Cloud metadata or administrative endpoints could be probed where network access permits
- Credentials configured for MDN delivery could be disclosed to an attacker-controlled destination
- Internal services may receive unexpected requests from a trusted network location
- The deployment's network segmentation and trust boundaries could be weakened
General mitigation guidance
Mitigation focuses on constraining outbound request destinations and reducing trust in values supplied by external AS2 partners.
Common defensive patterns include:
- Allowing asynchronous MDN delivery only to explicitly configured partner endpoints
- Validating destinations against strict allowlists rather than accepting arbitrary hosts or schemes
- Restricting outbound network connectivity from AS2 receivers to legitimate receipt-delivery endpoints
- Avoiding credentials on MDN requests unless they are valid exclusively for the approved destination
- Applying least privilege to network identities, service accounts, and outbound proxies
- Using network-layer controls to block access to internal administration, metadata, and loopback services
- Treating inbound destination fields as untrusted data and enforcing policy before initiating connections
Mitigation focuses on constraining outbound request destinations and reducing trust in values supplied by external AS2 partners.
Common defensive patterns include:
- Allowing asynchronous MDN delivery only to explicitly configured partner endpoints
- Validating destinations against strict allowlists rather than accepting arbitrary hosts or schemes
- Restricting outbound network connectivity from AS2 receivers to legitimate receipt-delivery endpoints
- Avoiding credentials on MDN requests unless they are valid exclusively for the approved destination
- Applying least privilege to network identities, service accounts, and outbound proxies
- Using network-layer controls to block access to internal administration, metadata, and loopback services
- Treating inbound destination fields as untrusted data and enforcing policy before initiating connections
How teams detect issues like this
Organizations can look for this vulnerability through:
- Static analysis rules identifying outbound HTTP client calls whose destinations derive from inbound message fields
- Code review checks for missing URI allowlists, scheme restrictions, DNS and IP validation, or redirect controls
- Tests that submit asynchronous MDN requests targeting internal, loopback, link-local, and unauthorized external destinations
- Egress firewall and proxy policies that alert on AS2 receiver connections outside approved partner ranges
- Network telemetry correlating AS2 inbound messages with unexpected outbound requests
- Secret-use monitoring for MDN credentials presented to unapproved hosts
- Automated security review tools that flag server-side request construction from untrusted input
Organizations can look for this vulnerability through:
- Static analysis rules identifying outbound HTTP client calls whose destinations derive from inbound message fields
- Code review checks for missing URI allowlists, scheme restrictions, DNS and IP validation, or redirect controls
- Tests that submit asynchronous MDN requests targeting internal, loopback, link-local, and unauthorized external destinations
- Egress firewall and proxy policies that alert on AS2 receiver connections outside approved partner ranges
- Network telemetry correlating AS2 inbound messages with unexpected outbound requests
- Secret-use monitoring for MDN credentials presented to unapproved hosts
- Automated security review tools that flag server-side request construction from untrusted input
Sources
| Source | Link |
|---|---|
| camel. | camel.apache.org/ |
| github. | github.com/ |
| github. | github.com/ |
| github. | github.com/ |
| issues. | issues.apache.org/ |
