JIRA issue permissions

[swarupa kunapuli]

How to restrict the user from changing the status of the issue of another user to whom the issue is assigned.

[Alexey Matveev]

Hello,
Try to add status property jira.permission.transition.assignee
More about status properties you can read here:
https://confluence.atlassian.com/adminjiraserver073/workflow-properties-861253674.html?_ga=2.117939657.1930125837.1508947508-1525820165.1497939199
Or you can defne allow only users with a certain permission condition on all transition
More about workflow conditions you can read here
https://confluence.atlassian.com/adminjiracloud/advanced-workflow-configuration-776636620.html#Advancedworkflowconfiguration-conditions