IndexError when decoding (old?) viewstate

[meme-lord]

This is a viewstate from an IIS/7.5 server.

Viewstate:

/wEPDwUJOTM0NDI1NDMxD2QWBGYPFgIeBFRleHQFbTwhRE9DVFlQRSBodG1sIFBVQkxJQyAiLS8vVzNDLy9EVEQgWEhUTUwgMS4wIFN0cmljdC8vRU4iICJodHRwOi8vd3d3LnczLm9yZy9UUi94aHRtbDEvRFREL3hodG1sMS1zdHJpY3QuZHRkIj5kAgQQZGQWAgIBD2QWBGYPZBYEZg9kFgIFC3dwOTI5MzI2MjM0D2QWAmYPZBYSAgEPDxYCHwAFE1JldHVybmluZyBDdXN0b21lcnNkZAIDDxYCHwAFbTxkaXYgY2xhc3M9InJjV2VsY29tZSI+UGxlYXNlIGxvZ2luIHVzaW5nIHRoZSB1c2VybmFtZSBhbmQgcGFzc3dvcmQgeW91IHJlY2VpdmVkIHdoZW4geW91IHNpZ25lZCB1cC4gPC9kaXY+DQpkAgUPDxYCHwAFCVVzZXJuYW1lOmRkAgcPDxYCHhBBdXRvQ29tcGxldGVUeXBlCyoqU3lzdGVtLldlYi5VSS5XZWJDb250cm9scy5BdXRvQ29tcGxldGVUeXBlARYCHgxhdXRvY29tcGxldGUFA29mZmQCCQ8PFgIfAAUJUGFzc3dvcmQ6ZGQCCw8PFgIfAQsrBAEWAh8CBQNvZmZkAg0PZBYCAgEPDxYCHwAFHURpZCB5b3UgZm9yZ2V0IHlvdXIgcGFzc3dvcmQ/FgIeB29uY2xpY2sFDXJldHVybiBmYWxzZTtkAg8PZBYCAgMPZBYCAgEPFgIeA3NyYwVDaHR0cHM6Ly9vcmRlcnMuaWdkZ2xhc3MuY29tOjQ0My9lU291cmNlMy8vaW1hZ2VzLy9sb2FkaW5nX0xvZ2luLmdpZmQCFw8WAh8AZWQCAg9kFgQCCQ9kFgwCAQ8PFgIfAAUUU2l0ZSBNb2RlOiBGdWxsIFNpdGVkZAILDw8WAh8AZWRkAhEPEGRkFgBkAhUPEGRkFgBkAhkPEGQQFQMSU2VsZWN0IEEgUGFuZS9ab25lD25ld0N1c3RvbWVyUGFuZRVyZXR1cm5pbmdDdXN0b21lclBhbmUVAxJTZWxlY3QgQSBQYW5lL1pvbmUPbmV3Q3VzdG9tZXJQYW5lFXJldHVybmluZ0N1c3RvbWVyUGFuZRQrAwNnZ2cWAWZkAicPFgIeB1Zpc2libGVoZAILDw8WAh4ISW1hZ2VVcmwFRWh0dHBzOi8vb3JkZXJzLmlnZGdsYXNzLmNvbTo0NDMvZVNvdXJjZTMvL2ltYWdlcy8vbG9hZGluZ19ibG9ja1VJLmdpZmRkAgEPZBYGAgEPDxYCHwVoZBYMAgEPDxYCHwAFBlNlbGVjdGRkAgUPDxYCHwAFBlN1Ym1pdGRkAgcPDxYCHwAFBlNlYXJjaGRkAgkPEGRkFgBkAgsPEGRkFgBkAg8PDxYCHwAFBlNlYXJjaGRkAgIPPCsAEgQAFCsACQ8WAh4OUGFydENocm9tZVR5cGUCAmRkZGQWBB4LQm9yZGVyQ29sb3IKpAEeBF8hU0ICEBYEHghDc3NDbGFzcwUSd2VicGFydF90aXRsZV9oaWRlHwkCAmRkZAIWAh8FaAcWAh8FaBAWBB4LQm9yZGVyU3R5bGULKiVTeXN0ZW0uV2ViLlVJLldlYkNvbnRyb2xzLkJvcmRlclN0eWxlAR8JAkBkAgMPPCsAEgQAFCsACQ8WAh8HAgJkZGRkFgQfCAqkAR8JAhAWBB8KBRJ3ZWJwYXJ0X3RpdGxlX2hpZGUfCQICZGRkAhYCHwVoBxYCHwVoEBYEHwsLKwUBHwkCQGRk+ajgpVPQKk0DfqIpz9BVt6PhM+PFyUodqFF0sMA3YVI=

Error:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/lib/python3.11/site-packages/viewstate/viewstate.py", line 44, in decode
    self.decoded, self.remainder = Parser.parse(self.body)
                                   ^^^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 35, in parse
    return Parser.registry[marker].parse(remain)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 136, in parse
    first, remain = Parser.parse(b)
                    ^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 35, in parse
    return Parser.registry[marker].parse(remain)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 137, in parse
    second, remain = Parser.parse(remain)
                     ^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 35, in parse
    return Parser.registry[marker].parse(remain)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 137, in parse
    second, remain = Parser.parse(remain)
                     ^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 35, in parse
    return Parser.registry[marker].parse(remain)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 202, in parse
    val, remain = Parser.parse(remain)
                  ^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 35, in parse
    return Parser.registry[marker].parse(remain)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 148, in parse
    third, remain = Parser.parse(remain)
                    ^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 35, in parse
    return Parser.registry[marker].parse(remain)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 202, in parse
    val, remain = Parser.parse(remain)
                  ^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 35, in parse
    return Parser.registry[marker].parse(remain)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 137, in parse
    second, remain = Parser.parse(remain)
                     ^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 35, in parse
    return Parser.registry[marker].parse(remain)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 202, in parse
    val, remain = Parser.parse(remain)
                  ^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 35, in parse
    return Parser.registry[marker].parse(remain)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 137, in parse
    second, remain = Parser.parse(remain)
                     ^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 35, in parse
    return Parser.registry[marker].parse(remain)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 202, in parse
    val, remain = Parser.parse(remain)
                  ^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 35, in parse
    return Parser.registry[marker].parse(remain)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 136, in parse
    first, remain = Parser.parse(b)
                    ^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 35, in parse
    return Parser.registry[marker].parse(remain)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/viewstate/parse.py", line 238, in parse
    l[idx] = val
    ~^^^^^
IndexError: list assignment index out of range