|Finding ID||Version||Rule ID||IA Controls||Severity|
|Generating a session identifier (ID) that is not easily guessed through brute force is essential to deter several types of session attacks. By knowing the session ID, an attacker can hijack a user session that has already been user-authenticated by the hosted application. The attacker does not need to guess user identifiers and passwords or have a secure token since the user session has already been authenticated. By generating session IDs that contain as much of the character set as possible, i.e., A-Z, a-z, and 0-9, the session ID becomes exponentially harder to guess.|
|Web Server Security Requirements Guide||2014-11-17|
|Check Text ( C-48197r2_chk )|
| Review the web server documentation and deployed configuration to determine what characters are used in generating session IDs. |
If the web server is not configured to use at least A-Z, a-z, and 0-9 to generate session identifiers, this is a finding.
|Fix Text (F-47268r2_fix)|
|Configure the web server to use at least A-Z, a-z, and 0-9 to generate session IDs.|