Vulnerability: Session Fixation, Reflected XSS, Code Execution
Affected Software: PivotX (http://pivotx.net/)
Affected Version: 2.3.10 (probably also prior versions)
Patched Version: 2.3.11
Risk: Medium-High

Session Fixation

Risk
----

Medium; If victim clicks link and logs in, then an attacker can log in

as the victim

POC
---

1. Send victim to:

http://localhost/pivotx_latest/pivotx/fileupload.php?sess=123
2. Victim logs in
3. Attacker sets PHPSESSID=123 and is now logged in as well

File Upload: Code Execution

Risk
----

Medium; attacker can upload PHP files and thus gain code execution

Description
-----------

It is possible to bypass the check for disallowed file extensions with

a filename like foo.php.php, which will be renamed to foo.php_.php,
leading to code execution.

Reflected XSS

Risk
----

Medium; arbitrary JavaScript execution

POC
---

        PHP_SELF is user supplied, and thus should not be considered

secure. It seems that most or all forms are affected by this.

http://localhost/pivotx_latest/pivotx/index.php/"><script>alert('xsstest')</script></script>?page=page&uid=3

http://localhost/pivotx_latest/pivotx/index.php/"><script>alert('xsstest')</script></script>?page=templates

http://localhost/pivotx_latest/pivotx/index.php/"><script>alert('xsstest')</script></script>?page=fileexplore
[… etc …]

Timeline

2015-05-27: Initial Report
2015-05-27: Vendor Confirmation
2015-06-05: Asking for Progress Update (no reply)
2015-06-14: Setting Disclose Date
2015-06-15: Vendor Confirmation
2015-06-17: Vendor Send Fix, Asking for Confirmation
2015-06-17: Confirmed Fix
2015-06-21: Vendor Releases Fix
2015-06-27: Disclosure

Source

http://software-talk.org/blog/2015/06/session-fixation-xss-code-execution-vulnerability-pivotx/