CAPEC-256 SOAP Array Overflow

An attacker sends a SOAP request with an array whose actual length exceeds the length indicated in the request. If the server processing the transmission naively trusts the specified size, then an attacker can intentionally understate the size of the array, possibly resulting in a buffer overflow if the server attempts to read the entire data set into the memory it allocated for a smaller array.

1. [Explore] [Identify target application] The adversary identifies a target application to perform the buffer overflow on. In this attack, adversaries look for applications that utilize SOAP as a communication mechanism. 2. [Experiment] [Find injection vector] The adversary identifies an injection vector to deliver the excessive content to the targeted application's buffer. 3. [Experiment] [Craft overflow content] The adversary crafts the content to be injected. If the intent is to simply cause the software to crash, the content need only consist of an excessive quantity of random data. If the intent is to leverage the overflow for execution of arbitrary code, the adversary crafts the payload in such a way that the overwritten return address is replaced with one of the adversary's choosing. 4. [Exploit] [Overflow the buffer] Using the injection vector, the adversary sends the crafted SOAP message to the program, overflowing the buffer.

• The targeted SOAP server must trust that the array size as stated in messages it receives is correct, but read through the entire content of the message regardless of the stated size of the array.

• If the server either verifies the correctness of the stated array size or if the server stops processing an array once the stated number of elements have been read, regardless of the actual array size, then this attack will fail. The former detects the malformed SOAP message while the latter ensures that the server does not attempt to load more data than was allocated for.