Memory leak in micronaut-core

Impact

Sending an invalid Content Type header leads to memory leak in DefaultArgumentConversionContext as this type is erroneously used in static state.

Patches

The problem is patched in Micronaut 3.2.7 and above.

Workarounds

The default content type binder can be replaced in an existing Micronaut application to mitigate the issue:

package example;

import java.util.List;
import io.micronaut.context.annotation.Replaces;
import io.micronaut.core.convert.ConversionService;
import io.micronaut.http.MediaType;
import io.micronaut.http.bind.DefaultRequestBinderRegistry;
import io.micronaut.http.bind.binders.RequestArgumentBinder;
import jakarta.inject.Singleton;

@Singleton
@Replaces(DefaultRequestBinderRegistry.class)
class FixedRequestBinderRegistry extends DefaultRequestBinderRegistry {

    public FixedRequestBinderRegistry(ConversionService conversionService,
                                      List<RequestArgumentBinder> binders) {
        super(conversionService, binders);
    }

    @Override
    protected void registerDefaultConverters(ConversionService<?> conversionService) {
        super.registerDefaultConverters(conversionService);
        conversionService.addConverter(CharSequence.class, MediaType.class, charSequence -> {
            try {
                return MediaType.of(charSequence);
            } catch (IllegalArgumentException e) {
                return null;
            }
        });
    }
}

References

Commit that introduced the vulnerability https://github.com/micronaut-projects/micronaut-core/commit/b8ec32c311689667c69ae7d9f9c3b3a8abc96fe3

For more information

If you have any questions or comments about this advisory:

• Open an issue in Micronaut Core
• Email us at [email protected]