CVE-2025-27636

Bypass/Injection vulnerability in Apache Camel components under particular conditions.

This issue affects Apache Camel: from 4.10.0 through <= 4.10.1, from 4.8.0 through <= 4.8.4, from 3.10.0 through <= 3.22.3.

Users are recommended to upgrade to version 4.10.2 for 4.10.x LTS, 4.8.5 for 4.8.x LTS and 3.22.4 for 3.x releases.

This vulnerability is present in Camels default incoming header filter, that allows an attacker to include Camel specific

headers that for some Camel components can alter the behaviours such as the camel-bean component, to call another method

on the bean, than was coded in the application. In the camel-jms component, then a malicious header can be used to send

the message to another queue (on the same broker) than was coded in the application. This could also be seen by using the camel-exec component

The attacker would need to inject custom headers, such as HTTP protocols. So if you have Camel applications that are

directly connected to the internet via HTTP, then an attacker could include malicious HTTP headers in the HTTP requests

that are send to the Camel application.

All the known Camel HTTP component such as camel-servlet, camel-jetty, camel-undertow, camel-platform-http, and camel-netty-http would be vulnerable out of the box.

In these conditions an attacker could be able to forge a Camel header name and make the bean component invoking other methods in the same bean.

In terms of usage of the default header filter strategy the list of components using that is:

• camel-activemq
• camel-activemq6
• camel-amqp
• camel-aws2-sqs
• camel-azure-servicebus
• camel-cxf-rest
• camel-cxf-soap
• camel-http
• camel-jetty
• camel-jms
• camel-kafka
• camel-knative
• camel-mail
• camel-nats
• camel-netty-http
• camel-platform-http
• camel-rest
• camel-sjms
• camel-spring-rabbitmq
• camel-stomp
• camel-tahu
• camel-undertow
• camel-xmpp

The vulnerability arises due to a bug in the default filtering mechanism that only blocks headers starting with Camel, camel, or org.apache.camel.. 

Mitigation: You can easily work around this in your Camel applications by removing the headers in your Camel routes. There are many ways of doing this, also globally or per route. This means you could use the removeHeaders EIP, to filter out anything like cAmel, cAMEL etc, or in general everything not starting with Camel, camel or org.apache.camel..

Weakness

The product does not properly account for differences in case sensitivity when accessing or determining the properties of a resource, leading to inconsistent results.

Affected Software

Extended Description

Improperly handled case sensitive data can lead to several possible consequences, including:

Potential Mitigations

• Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
• When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
• Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.

References

• https://camel.apache.org/security/CVE-2025-27636.html
• https://issues.apache.org/jira/browse/CAMEL-21828
• https://lists.apache.org/thread/l3zcg3vts88bmc7w8172wkgw610y693z
• http://www.openwall.com/lists/oss-security/2025/03/09/1
• https://camel.apache.org/security/CVE-2025-27636.txt.asc
• https://github.com/akamai/CVE-2025-27636-Apache-Camel-PoC/blob/main/src/main/java/com/example/camel/VulnerableCamel.java