Steps to reproduce:
1) deploy a process with generated task form (the form should include at least on field of type string, whereby the defaultValue is retrieved by the variable "foo")
2) start a process instance with a variable foo with the value This is a "test" message.
3) go to tasklist
4) open the corresponding task
Only This is a is displayed inside the input field.
This is a "test" message. is displayed inside the input field.
The resulting html input field in the browsers looks as follows: