Facebook Google Plus Twitter LinkedIn YouTube RSS Menu Search Resource - BlogResource - WebinarResource - ReportResource - Eventicons_066 icons_067icons_068icons_069icons_070

MikroTik WinBox Path Traversal

Medium

Synopsis

MikroTik WinBox before 3.21 is vulnerable to a path traversal issue that allows an attacker to write files anywhere on the system where WinBox has write privileges.

When WinBox connects to a router, it downloads the list file from /home/web/webfig/. This file contains a list of files that WinBox should download in order to obtain package descriptions. WinBox downloads these files and stores them on the client's system within the MikroTik roaming directory: C:\Users\[username]\AppData\Roaming\Mikrotik\Winbox.

The name of the created files come directly from the downloaded list file. For example, this is a line from list:

{ crc: 164562873, size: 1149, name: "advtool.jg", unique: "advtool-fc1932f6809e.jg", version: "6.39.3" }

WinBox will use the name "advtool.jg" as the filename in the roaming directory. However, WinBox doesn't do any type of checking for directory traversal on these files. So if presented with:

{ crc: 164562873, size: 1149, name: "../../../../../../../Users/Public/lol.txt", unique: "advtool-fc1932f6809e.jg", version: "6.39.3" }

Then WinBox would create the file C:\Users\Public\lol.txt and fill it with contents provided by the attacker.

An attacker can exploit this bug by getting a victim to connect to a malicious MikroTik router, a fake router (see our PoC for CVE-2019-3981) , or via a man in the middle attack. The attacker can then perform the downgrade attack described in TRA-2020-01. The client will then try to download the files from the attacker.

A proof of concept has been uploaded to our research GitHub repository. The PoC listens on port 8291. When WinBox connects to it, the script will ignore the ECSRP message so that the client switches to Diffie-Hellman. After the login is complete, the script serves up a malicious list file and eventually writes the file C:\Users\Public\lol.txt with the contents "hello mikrotik".

Solution

Upgrade to Winbox 3.21

Disclosure Timeline

January 16, 2020 - Tenable discloses issue to MikroTik. 90 days is April 15, 2020.
January 17, 2020 - MikroTik appears to indicate path traversal will be fixed when DH is fixed (no set date).
January 17, 2020 - Tenable reiterates that the path traversal issue is separate from the DH problem.
January 20, 2020 - Tenable and MikroTik exchange emails on RouterOS architecture.
February 6, 2020 - Tenable notices a post on Reddit indicating WinBox 3.21 fixes the reported issues.

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 [email protected]

Risk Information

CVE ID: CVE-2020-5720
Tenable Advisory ID: TRA-2020-07
Credit:
Jacob Baines
CVSSv2 Base / Temporal Score:
4.3 / 3.6
CVSSv2 Vector:
AV:N/AC:M/Au:N/C:N/I:P/A:N
Affected Products:
MikroTik WinBox before 3.21
Risk Factor:
Medium
Additional Keywords:
CWE-22

Advisory Timeline

February 6, 2020 - Initial Release

Tenable Vulnerability Management

Enjoy full access to a modern, cloud-based vulnerability management platform that enables you to see and track all of your assets with unmatched accuracy.

Your Tenable Vulnerability Management trial also includes Tenable Lumin and Tenable Web App Scanning.

Tenable Vulnerability Management

Enjoy full access to a modern, cloud-based vulnerability management platform that enables you to see and track all of your assets with unmatched accuracy. Purchase your annual subscription today.

100 assets

Choose Your Subscription Option:

Buy Now

Tenable Vulnerability Management

Enjoy full access to a modern, cloud-based vulnerability management platform that enables you to see and track all of your assets with unmatched accuracy.

Your Tenable Vulnerability Management trial also includes Tenable Lumin and Tenable Web App Scanning.

Tenable Vulnerability Management

Enjoy full access to a modern, cloud-based vulnerability management platform that enables you to see and track all of your assets with unmatched accuracy. Purchase your annual subscription today.

100 assets

Choose Your Subscription Option:

Buy Now

Tenable Vulnerability Management

Enjoy full access to a modern, cloud-based vulnerability management platform that enables you to see and track all of your assets with unmatched accuracy.

Your Tenable Vulnerability Management trial also includes Tenable Lumin and Tenable Web App Scanning.

Tenable Vulnerability Management

Enjoy full access to a modern, cloud-based vulnerability management platform that enables you to see and track all of your assets with unmatched accuracy. Purchase your annual subscription today.

100 assets

Choose Your Subscription Option:

Buy Now

Try Tenable Web App Scanning

Enjoy full access to our latest web application scanning offering designed for modern applications as part of the Tenable One Exposure Management platform. Safely scan your entire online portfolio for vulnerabilities with a high degree of accuracy without heavy manual effort or disruption to critical web applications. Sign up now.

Your Tenable Web App Scanning trial also includes Tenable Vulnerability Management and Tenable Lumin.

Buy Tenable Web App Scanning

Enjoy full access to a modern, cloud-based vulnerability management platform that enables you to see and track all of your assets with unmatched accuracy. Purchase your annual subscription today.

5 FQDNs

$3,578

Buy Now

Try Tenable Lumin

Visualize and explore your exposure management, track risk reduction over time and benchmark against your peers with Tenable Lumin.

Your Tenable Lumin trial also includes Tenable Vulnerability Management and Tenable Web App Scanning.

Buy Tenable Lumin

Contact a Sales Representative to see how Tenable Lumin can help you gain insight across your entire organization and manage cyber risk.

Try Tenable Nessus Professional Free

FREE FOR 7 DAYS

Tenable Nessus is the most comprehensive vulnerability scanner on the market today.

NEW - Tenable Nessus Expert
Now Available

Nessus Expert adds even more features, including external attack surface scanning, and the ability to add domains and scan cloud infrastructure. Click here to Try Nessus Expert.

Fill out the form below to continue with a Nessus Pro Trial.

Buy Tenable Nessus Professional

Tenable Nessus is the most comprehensive vulnerability scanner on the market today. Tenable Nessus Professional will help automate the vulnerability scanning process, save time in your compliance cycles and allow you to engage your IT team.

Buy a multi-year license and save. Add Advanced Support for access to phone, community and chat support 24 hours a day, 365 days a year.

Select Your License

Buy a multi-year license and save.

Add Support and Training

Try Tenable Nessus Expert Free

FREE FOR 7 DAYS

Built for the modern attack surface, Nessus Expert enables you to see more and protect your organization from vulnerabilities from IT to the cloud.

Already have Tenable Nessus Professional?
Upgrade to Nessus Expert free for 7 days.

Buy Tenable Nessus Expert

Built for the modern attack surface, Nessus Expert enables you to see more and protect your organization from vulnerabilities from IT to the cloud.

Select Your License

Buy a multi-year license and save more.

Add Support and Training