icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons icons_061

[R2] Dell SonicWALL /appliance/license.jsp Serial Number Disclosure Remote Privilege Escalation

Medium

Synopsis

While writing a detection plugin for VulnDB 142008 (no CVE), Tenable discovered an additional vulnerability that allows a remote, unauthenticated attacker to gain admin access to the Universal Management Host (UMH) or the Universal Management Appliance (UMA) interface of a Dell SonicWALL GMS/Analyzer system.

The product is designed to allow users to reset the password of the user 'admin' to 'password'. To do so, the user must provide a valid password reset key (pwdResetKey). That key is the serial number (SN) of the product license encrypted with a key formed by concatenating the first 6 bytes of the SN and a magic string (we are not disclosing but not difficult to figure out). The encryption algorithm is 3DES using ECB mode. So the secrecy of the pwdResetKey solely depends on the SN, which is accessible without authentication via the /appliance/license.jsp script. If the product is not registered/licensed, /appliance/license.jsp will show:


[margay@wiedii sonicwall]# curl -s http://192.168.168.129/appliance/license.jsp | grep -i "Serial Number"
<td colspan=3 align=right class=bodyFont> Serial Number: <font class="controlFont">Not Registered</font> </td>

In this case, the string "password" is used for SN during pwdResetKey computation. Knowing the SN, the attacker can compute the pwdResetKey and reset the admin password to 'password'. She can then login and access the full functionalities in UMH/UMA, which includes, but not limited to, the following:

  • Apply Service Packs/HotFixes to the product. This could potentially allow the attacker to upload customized/modified product files with malicious intent.
  • Configure Host Role. The attacker can change the role configuration, disable/stop the services configured for the role.
  • Change the password for the Administrator account (admin). The attacker can deny UMH/UMA access to legitimate users.

The pwdResetKey is validated by the com.sonicwall.appliance.servlets.AuthenticationFilter servlet.

Note that while the CVSSv2 score reflects partial integrity (e.g. manipulation of a password), the immediate follow-up impact is complete control over the software. This score is a bit misleading, but in keeping with the CVSSv2 guidelines.

Solution

Dell has released version 8.2 of SonicWALL GMS which addresses this issue.

Disclosure Timeline

2016-08-12 - Issue Discovered
2016-08-18 - Submitted to ZDI for consideration, case bmartin0015 opened
2016-08-25 - ZDI declines, "product and bug type combo is not strong at this time"
2016-09-07 - Asked @SonicWALL on Twitter for desired vuln reporting email address
2016-09-07 - @SonicWALL replies to email their social media team, and they will find out
2016-09-07 - JF at SonicWALL says she will take the report and figure out where it goes
2016-09-07 - Tenable sends full details
2016-09-09 - JF at SonicWALL says she passed it on to Engineering upon receipt, they will reach out next
2016-10-10 - Ping vendor (JF) for update
2016-10-19 - Ping vendor (JF) for update, still no contact from Engineering
2016-10-19 - OOO reply from JF, returning 10/21/2016
2016-10-20 - JF replies, says issue escalated and Engineering will be in touch
2016-10-25 - LW from engineering replies, says will be fixed in 8.2 (early Nov), and a patch for 8.1 (late Nov)
2016-10-28 - SonicWall article date for 8.2 release, despite "Early Nov" bit from Dell
2016-11-24 - Pinged vendor for update
2016-11-28 - Vendor confirms 8.2 released on schedule, changelog refs issue as ID 178678

All information within TRA advisories is provided “as is”, without warranty of any kind, including the implied warranties of merchantability and fitness for a particular purpose, and with no guarantee of completeness, accuracy, or timeliness. Individuals and organizations are responsible for assessing the impact of any actual or potential security vulnerability.

Tenable takes product security very seriously. If you believe you have found a vulnerability in one of our products, we ask that you please work with us to quickly resolve it in order to protect customers. Tenable believes in responding quickly to such reports, maintaining communication with researchers, and providing a solution in short order.

For more details on submitting vulnerability information, please see our Vulnerability Reporting Guidelines page.

If you have questions or corrections about this advisory, please email advisories@tenable.com