Document Title: =============== Flowdock API Bug Bounty #3 - (Invite) Persistent Web Vulnerability References (Source): ==================== http://www.vulnerability-lab.com/get_content.php?id=1574 Release Date: ============= 2015-09-24 Vulnerability Laboratory ID (VL-ID): ==================================== 1574 Common Vulnerability Scoring System: ==================================== 3.8 Product & Service Introduction: =============================== Chat & inbox for teams.. One place to talk and stay up-to-date. Flowdock is a team collaboration app for desktop, mobile & web. Work on things that matter, be transparent and solve problems across tools, teams & time zones. Try it for free for 30 days. Keeping Flowdock`s environment and customer data safe and secure is a top priority for us. Find more details on our Help pages. Don`t hesitate to contact us at support@flowdock.com should you have any questions about Flowdock`s security. (Copy of the Vendor Homepage: https://www.flowdock.com/security ) Abstract Advisory Information: ============================== The Vulnerability Laboratory Research Team discovered an application-side input validation web vulnerability in the official Flowdock online service web-application. Vulnerability Disclosure Timeline: ================================== 2015-08-16: Researcher Notification & Coordination (Benjamin Kunz Mejri) 2015-08-17: Vendor Notification (Flowdock Security Team - Bug Bounty Program) 2015-08-17: Vendor Response/Feedback (Flowdock Security Team - Bug Bounty Program) 2015-08-18: Vendor Fix/Patch (Flowdock Developer Team) 2015-09-24: Public Disclosure (Vulnerability Laboratory) Discovery Status: ================= Published Affected Product(s): ==================== Rally Software Product: Flowdock - Online Service (Web-Application) [API] 2015 Q3 Exploitation Technique: ======================= Remote Severity Level: =============== Medium Technical Details & Description: ================================ An application-side input validation web vulnerability has been discovered in the official Flowdock online-service web-application. The vulnerability allows remote attackers to inject own malicious script codes to the application-side of the vulnerable context function or service module. The vulnerability is located in the flow name and flow description values of the Invite your Team (Flowdock Rest API) module POST method request. Remote attackers with low privilege application user accounts are able to inject own malicious script codes to the application-side of the service. The request method to inject malicious context is POST and the attack vector is located on the application-side of the flowdock api web-service. Remote attackers are able to inject malicious script codes to the application-side to compromise flowdock rest api dashboard (messages) by session manipulation or session evasion attacks. The attacker inject via name and description values malicious payloads which demonstrates the injection point and the execution point is in the insecure validated message inbox of the main deashboard. The security risk of the persistent input validation web vulnerability is estimated as medium with a cvss (common vulnerability scoring system) count of 3.8. Exploitation of the persistent input validation web vulnerability requires a low privilege web-application user account and low user interaction. Successful exploitation of the vulnerability results in session hijacking, persistent phishing attacks, persistent redirect to external sources and persistent manipulation of affected or connected service module context. Request Method(s): [+] POST Vulnerable Module(s): [+] Invite your Team (Flowdock Rest API) Vulnerable Parameter(s): [+] Flow Name [+] Flow Description Proof of Concept (PoC): ======================= The security vulnerability can be exploited by remote attackers with low privilege application user account and low user interaction. For security demonstration or to reproduce the security vulnerability follow the provided information and steps below to continue. Manual steps to reproduce the vulnerability ... 1. Login to your account at the flowdock website 2. Surf to the main dasboard module 3. Click the invite your team button 4. Switch to the flow menu bar 5. Inject malicious script code test payload to the name and description of flowdock inputs via api 6. Save the input and return back to the module by refresh or cancel after update 7. The code executes in the message board but also in the message dasboard index were the user has been invited to grant access 8. Successful reproduce of the vulnerability in flowdock api and main dashbaord! Note: Use tamper data in mozilla to manipulate the session values and to approve the existence of the vulnerability! Execution Point: https://www.flowdock.com/app/vulnerability-lab/main https://www.flowdock.com/app/vulnerability-lab/main/messages/6 Inject Point via Invite: https://www.flowdock.com/app/vulnerability-lab/main/settings/people > https://www.flowdock.com/app/vulnerability-lab/main/settings/flow > Flow description & Flow description PoC: ../(Vulnerability Lab) - Flowdock.htm ../(Vulnerability Lab) - Flowdock_2.htm --- PoC Session Logs [POST] --- 14:45:37.893[547ms][total 547ms] Status: 200[OK] PATCH https://www.flowdock.com/rest/flows/vulnerability-lab/main Load Flags[LOAD_BACKGROUND LOAD_BYPASS_LOCAL_CACHE_IF_BUSY ] Größe des Inhalts[1038] Mime Type[application/json] Request Header: Host[www.flowdock.com] User-Agent[Mozilla/5.0 (Windows NT 6.3; WOW64; rv:39.0) Gecko/20100101 Firefox/39.0] Accept[application/json, text/javascript, */*; q=0.01] Accept-Language[de,en-US;q=0.7,en;q=0.3] Accept-Encoding[gzip, deflate] Content-Type[application/json; charset=UTF-8] X-CSRF-Token[F1Gu5THaCu+boEBc4Vh03Hp6/gdtLDfJmhYp7CemM3lfc2s5qHBmhPztO9CFR5xRsBs5HmBpFwMfpl7DfePR6Q==] X-Requested-With[XMLHttpRequest] Referer[https://www.flowdock.com] Content-Length[27] Cookie[_flowdock_session=dGRDOWNBUzY0ZUI5NDBuTHpUaG54TWc2V1FTWjBXeTRCL0x2NU50VDUwNGszSEZSaUZqZUFBKzFsUWdZOVdVcEdjR1lvVnpwZmtYd080NE9OWUtLMnNqaG9qTFFSaUVsa0g2NnlGaUhvMWtvRlhWZmFuTlduMk8rM05jOERoOURPcGx5YnlXZ0w4blg1NlRMd0d4b2poMmwyMXl4czdFMGhnNEFuWTlWbTd1bEFzUEZaT2luTXJ1c1NlZDhpZnNZVGxvR1VhOGd0Y2MwTVA1dUVJUUVKTjRST09OcmNsVURsVE9pMGJUMER0RkE1MG9zbk9PMmVIK1FFbjM3YVdUNy0taytKRWs0Ti9zaUJhQWdZM0ZzY0hvZz09--cbdbb966304bbcb2c80d374170b33c62ead6d858; 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domain=.flowdock.com; path=/; secure; HttpOnly] X-Server-Id[475b6e71889f174f61273dab9d11d64422779f4c] Vary[Accept-Encoding] Content-Encoding[gzip] Content-Length[1038] 14:45:41.389[279ms][total 279ms] Status: 200[OK] GET https://www.flowdock.com/rest/organizations Load Flags[LOAD_BACKGROUND LOAD_BYPASS_LOCAL_CACHE_IF_BUSY ] Größe des Inhalts[462] Mime Type[application/json] Request Header: Host[www.flowdock.com] User-Agent[Mozilla/5.0 (Windows NT 6.3; WOW64; rv:39.0) Gecko/20100101 Firefox/39.0] Accept[application/json, text/javascript, */*; q=0.01] Accept-Language[de,en-US;q=0.7,en;q=0.3] Accept-Encoding[gzip, deflate] X-CSRF-Token[F1Gu5THaCu+boEBc4Vh03Hp6/gdtLDfJmhYp7CemM3lfc2s5qHBmhPztO9CFR5xRsBs5HmBpFwMfpl7DfePR6Q==] X-Requested-With[XMLHttpRequest] Referer[https://www.flowdock.com] Cookie[_flowdock_session=eFk1WlAzZ1NlbmtFbW9kNzdFUEowZFlCRUJtR0FVRTMvaGpWaklmeElXYXIxc0hWemNGRGxwRTY3c0RMZ2xyRDlsWHNzaDFSTmFjajg1TjFWUnFsTnlZQ2FQQUZMMHd6TXVwRjg3M1RRRUg4MnVlNjdhQ1FHbjI1eHFmb2Exd3ZUVmw5Z2t2cURodDBKeTJTQXYyemdqaVNmeHdjMWZpOGZRVS9LZHV0V0x2WWgyR3NVZzUxNnZLbHJxNWdaOFVMRVRrUHNkM3d0NkJ0VWZuWlNSUFJwM1N0emFjc3k1ZjVGOENSYzk1U1B1KzlWV0tieWlyNStWVnl1ZmlXeGFhYy0tRjZ3VzZmendieitZNzFTOFd0RUJjUT09--87cdea353b5110514da2f5f0aa971ef9b2a27f02; 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domain=.flowdock.com; path=/; secure; HttpOnly] X-Server-Id[45c836f72727be03bd8c2ae92cedbf6a75a556bc] Vary[Accept-Encoding] Content-Encoding[gzip] Content-Length[462] 14:45:41.671[269ms][total 269ms] Status: 200[OK] GET https://www.flowdock.com/rest/flows/vulnerability-lab/main/legacy_sources Load Flags[LOAD_BACKGROUND LOAD_BYPASS_LOCAL_CACHE_IF_BUSY ] Größe des Inhalts[424] Mime Type[application/json] Request Header: Host[www.flowdock.com] User-Agent[Mozilla/5.0 (Windows NT 6.3; WOW64; rv:39.0) Gecko/20100101 Firefox/39.0] Accept[application/json, text/javascript, */*; q=0.01] Accept-Language[de,en-US;q=0.7,en;q=0.3] Accept-Encoding[gzip, deflate] X-CSRF-Token[F1Gu5THaCu+boEBc4Vh03Hp6/gdtLDfJmhYp7CemM3lfc2s5qHBmhPztO9CFR5xRsBs5HmBpFwMfpl7DfePR6Q==] X-Requested-With[XMLHttpRequest] Referer[https://www.flowdock.com] Cookie[_flowdock_session=ZEp0MWVJektoN2FOY3pvelduOFRqUEp6ajJXdU55VTFKcHlaWDNTYU9wN05XYjBNUXhqZCtQZzZHVzRUcUw5SkY3alhHSFVpMmVrWE5IK1ZyUkhVZGRXT0xoZDJNYmtNQnMySjZTRi9oZzNZWDJOMzVlQnU2OFZEdllBdTJEcHVHaWFBTkNuL0NRK3FMSDlGL2E3RXU0dTdGa3ZRa3p0S0dLdVM3Ykl1bml2TmptUGhwVzJ3L05YTUI3NTZ1VlNYM2Q1UUYvQW9KbTVNc3o0ZG93elZxbXFUdjRRbDVQUFlhaGtBTDRjQWxRS1RnUk5LUTkyNnovUEhvbGUyRVljMS0tdkxDdjhrRnRMa3dreHpyOFVPSE12QT09--fccec74f5dea50c4179807e560d1e396d41c2396; _ga=GA1.2.316225615.1439815246; _gat=1; ga_cid=316225615.1439815246; __ar_v4=NVE6VSAVAFEITPQZLCROVA%3A20150816%3A6%7CN4SGXQCDSJGPZCWP5DGWWO%3A20150816%3A6%7CP3GQR6LVEJFUDLS6YOOZNQ%3A20150816%3A6; login=1; referrer=Imh0dHBzOi8vd3d3LmZsb3dkb2NrLmNvbS9zaWdudXAi--3cec34efe6cf016e98a271766e3987690fac2632; logged_in=1439815538] Connection[keep-alive] Response Header: Date[Mon, 17 Aug 2015 12:45:43 GMT] status[200 OK] Strict-Transport-Security[max-age=31557600] X-Frame-Options[SAMEORIGIN] X-XSS-Protection[1; mode=block] x-content-type-options[nosniff] Flowdock-User[171908] Content-Type[application/json; charset=utf-8] Cache-Control[private, no-store, no-cache] X-Request-ID[63eb2e65-2171-4a74-99e0-1b4585d5911d] X-Runtime[0.061483] Set-Cookie[_flowdock_session=QzN3WHZtc1lzdDVtNGpLTGYzNk9vdFZxbnR6cGV1Rzl5WXVFTUo1NnlYSVM5WVNQZU8xOXVxRDdSTEErR2J0R3FSWU94U2xLZmFibWhzWjdEVFNTSGRqWCtDbmFCbnNuWW9WcXJhaldvREx5K0I4WGd3VFhxRHNXSEgxWitNcGNFV1F5LzBNaTd4TDY0QXVnUmdUM094NmlpdlRNQy85L0xJcnN1akFRQVZyRjN2MnFzU09lUldoZE1sUElmLzFoSjVkZGh2dFBYaXhnQ210K2JCVE90YWs1NTJiM05Wem5zZnJyZzhxYk4zVG1qdUFId1VBOVlJZ1pCYWpGV29vTy0tUXBvSGc3cm1NVXdXcFVNeUtJV1c0Zz09--fe722bc41c75c489788151b2df42becbf7e127f2; domain=.flowdock.com; path=/; secure; HttpOnly] X-Server-Id[d4741d0780602ce7b33aca93992eb68edf43247c] Vary[Accept-Encoding] Content-Encoding[gzip] Content-Length[424] 14:45:49.468[349ms][total 349ms] Status: 200[OK] PATCH https://www.flowdock.com/rest/flows/vulnerability-lab/main Load Flags[LOAD_BACKGROUND LOAD_BYPASS_LOCAL_CACHE_IF_BUSY ] Größe des Inhalts[1043] Mime Type[application/json] Request Header: Host[www.flowdock.com] User-Agent[Mozilla/5.0 (Windows NT 6.3; WOW64; rv:39.0) Gecko/20100101 Firefox/39.0] Accept[application/json, text/javascript, */*; q=0.01] Accept-Language[de,en-US;q=0.7,en;q=0.3] Accept-Encoding[gzip, deflate] Content-Type[application/json; charset=UTF-8] X-CSRF-Token[F1Gu5THaCu+boEBc4Vh03Hp6/gdtLDfJmhYp7CemM3lfc2s5qHBmhPztO9CFR5xRsBs5HmBpFwMfpl7DfePR6Q==] X-Requested-With[XMLHttpRequest] Referer[https://www.flowdock.com] Content-Length[196] Cookie[_flowdock_session=UklHQ24yeS9SOHhuV3VaVVM2Z1hIdTVIWm9NOFMxY2lReUkxdDBVVmJDQzRUaU43dHRURWI1djhKeEF2NC93YndlWDg0M0t2K0ZjUUhGYmVvMUN3eG13bk91Uk8wMG9EMUhBYWpDTDR0YVA2ZFNCQkVzSzNXRmUvQzBMR3hRT0JDTkVWYXI0MlJJWnVvSzRXMmRzN0drTzNNUjZjWlZ1RnpVZ2NHTkltZzBFSUF0QWlqRGlVQWY2VHlmZHJzSjdENmwzZlQ3M0pzNzdJSXhkbXNkVE5BdSt5RG1RVEFrcnVKTGQrUFFpbm1tQS9EMW1oRG9zbzIvZ2x2aTlHWjN4dS0tRSsyTjAzeDhBWnNwWm9wRXk0TjFHZz09--a11946082028d7dff6b0052618400ad6b6d15c4a; 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