Apache Camel Redis: unsafe Java deserialization lets published messages run code

Deserialization of Untrusted Data vulnerability in Apache Camel Spring Redis component.

This issue affects Apache Camel: from 2.11.0 before 4.18.5, from 4.19.0 before 4.22.1.

RedisConfiguration.getSerializer lazily built a bare JdkSerializationRedisSerializer whenever no serializer option was configured, and that instance was used for every read the component performs. Spring's implementation delegates through DeserializingConverter to DefaultDeserializer, which reads the bytes with a ConfigurableObjectInputStream and installs no java.io.ObjectInputFilter on the stream, so an arbitrary serialized class graph was materialised and its readObject method executed. RedisConsumer.setBody applied that serializer to the raw bytes of every message published to the subscribed channels, before the Exchange was constructed and therefore before any route logic could inspect the message, so an actor able to issue PUBLISH on a subscribed channel reached the deserialization sink directly. The same default serializer backed the RedisTemplate built by RedisConfiguration.createDefaultTemplate, so the producer read commands GET, HGET, HGETALL and HVALS deserialized whatever was stored in the Redis keyspace, and SpringRedisIdempotentRepository shared that template. Configuring a custom redisTemplate did not close the consumer path, because RedisConsumer.setBody reads getSerializer directly rather than the serializer attached to the template, so a deployment that had wired a String serializer into its own template remained exposed on the consumer side unless it also set the serializer option. The component never constructed a java.io.ObjectInputStream itself, which is why earlier passes over the Camel codebase for unfiltered Java deserialization did not reach it. The behaviour dates back to the introduction of the component, first released in 2.11.0, and was unchanged until this fix.

Users are recommended to upgrade to version 4.23.0, which fixes the issue. If users are on the 4.22.x releases stream, then they are suggested to upgrade to 4.22.1. If users are on the 4.18.x releases stream, then they are suggested to upgrade to 4.18.5. The 4.14.x releases stream and earlier reached end of life before this issue was resolved and will not receive a fix, so deployments on those lines must move to a supported release. For deployments that cannot upgrade immediately, set the JVM-wide jdk.serialFilter system property, which the affected code path honours because it reads through a java.io.ObjectInputStream, for example -Djdk.serialFilter=!java.net.;java.;javax.;org.apache.camel.;!* ; or set the serializer endpoint option to a serializer that does not use Java serialization, such as StringRedisSerializer, noting that this must be set as the serializer option and not only on a custom redisTemplate. As defence in depth, require authentication on the Redis instance and restrict which clients may publish to the subscribed channels, and do not expose a Redis instance consumed by Camel to untrusted networks.