Risks of Modified Cookies

Now, at the end of the year, cookies are increasingly circulating again. Where do they come from, and how can the client deal with them? Modified cookies in particular can cause problems, both on the client and on the server. Being properly prepared can help you manage this risk.

Modified cookies

According to the WBF (Windows Baking Foundation), modified cookies have increasingly been circulating again of late. As with all kinds of cookies, they are transmitted from the server to the client by way of the REST (Restlessly Eating Sweets Transport) protocol. Once they have arrived at and been processed by the client, however, they can further affect the client’s system. The most dangerous version causes the client to send additional cookie requests to the server. This is dangerous for both the client and the server. Too many stored cookies may cause the client to respond with an overflow exception. In the worst case, too many client requests will trigger a 503 response by the server, i.e. service unavailable. If the client sends the subsequent cookie requests in too rapid succession, it is possible that the resource will not be able to be found because the processing has not yet been completed.

What causes this behavior on the server side? Even standard cookies can overload the server if there are too many requests. The modified cookies, however, require additional resources that have to be requested first, and that slow down the processing. Objects of the Mac.Adam.IA type are the most important additional resource. They must first be procured via a CDN (Christmas Delivery Nutwork). Usually, the latter are marketplaces that require a face-to-face connection. Once the server has allocated the resources, they have to be split into small pieces called chunks. This requires special hardware, namely a splitter. Furthermore, contrary to the standard procedure, the white bytes are required instead of the black ones. They, too, have to be split. The input is further processed by means of the standard build process on an oVEN server. In addition to the bUTTeR package, the mail library and the sweetnER DLL should be included as well. Salt, which is known from cryptography, is also very important. All the components are blended, and the compilation is then made ready for delivery in a second build step. The distribution of the blended components is important at this point. They must not be coupled too closely in order to avoid creating dependencies that are difficult to undo. A 3×3 matrix has proven to be ideal. This second build step usually takes 10 minutes. After this, you have nine artifacts at your disposal that have to be shifted to a grid before deployment. In other words, the build process is a bottleneck. A single build server generates a maximum of 54 artifacts per hour, not taking the compilation process into account. If more than 54 client requests are received, the server is overloaded and responds with the usual status codes.

On the client’s side, the simultaneous installation of too many cookies can cause an overflow. In the worst case, this can result in a system crash, after which the client cannot process any more cookies. Curbing the client helps in this case. It is important to ensure that the client does not have to process several cookies in parallel, and also that it stops accepting more cookies in time. The intake capacity depends on the client and has to be determined on a case-by-case basis.

In principle, the processing of cookies by the client is not harmful, but it needs to be monitored. The server should be prepared for the frequent requests occurring at this time in order to prevent denial-of-service attacks. Several parallel build servers can be useful in this context to ensure load balancing.

You can find the build script below:

    <recipe>
    <ingredients>
    <ingredient id="1" amount="280" unit="g">Mail</ingredient>
    <ingredient id="2" amount="1" unit="tl">Natron</ingredient>
    <ingredient id="3" amount="1" unit="tl">Salt</ingredient>
    <ingredient id="4" amount="250" unit="g" style="soft">bUTTeR</ingredient>
    <ingredient id="5" amount="190" unit="g" color="white">sucER</ingredient>
    <ingredient id="6" amount="135" unit="g" color="brown">sucER</ingredient>
    <ingredient id="7" amount="1" unit="pack">Vanilla</ingredient>
    <ingredient id="8" amount="2" unit="pieces">Easter egg</ingredient>
    <ingredient id="9" amount="200" unit="g" color="white" flavor="chocolate">Byte</ingredient>
    <ingredient id="10" amount="200" unit="g">Mac.Adam.IA</ingredient>
    </ingredients>
    <instructions>
    <instruction id="1" text="Heat the oVEN server up to 190."></instruction>
    <instruction id="2" text="Mix ingredients in separate sandbox.">
      <ref:ingredient ref="1" />
      <ref:ingredient ref="2" />
      <ref:ingredient ref="3" />
    </instruction>
    <instruction id="3" text="Mix ingredients in separate sandbox." style="creamy">
      <ref:ingredient ref="4" />
      <ref:ingredient ref="5" />
      <ref:ingredient ref="6" />
      <ref:ingredient ref="7" />
    </instruction>
    <instruction id="4" text="Add ingredients" style="add separately" basedOnInstruction="3" >
      <ref:ingredient ref="8" />
    </instruction>
    <instruction id="5" text="Add ingredients" basedOnInstruction="3">
      <ref:instruction ref="2" />
    </instruction>
    <instruction id="6" text="Add ingredients" basedOnInstruction="3">
      <ref:ingredient ref="9" mode="chunked" />
      <ref:ingredient ref="10" mode="chunked" />
    </instruction>
    <instruction id="7" text="Put 3x3 objects in build server" size="el"></instruction>
    <instruction id="8" text="Run build process" timespan="10"></instruction>
    <instruction id="9" text="Wait for completion outside build server" timespan="2" mode="cool"></instruction>
    <instruction id="1ß" text="Deploy on grid" mode="cool"></instruction>
    <instructions>
    </recipe>

This post was written by: