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

[R2] Cisco IOS Smart Install Client Feature Config / Boot Image File List Upload Remote Code Execution

High

Synopsis

In 2013, Tenable Network Security reported a file upload remote code execution flaw in Cisco IOS Smart Install Client via the Zero Day Initiative (ZDI), tracked by Cisco as CSCub55790. Based on subsequent testing, it appears this issue was not fully fixed in the patches released by Cisco. Cisco 2960G switches running c2960-lanbasek9-mz.150-2.SE8.bin (compiled on 14-May-15) are still vulnerable.

This vulnerability allows the attacker to replace the startup configuration file and the booting IOS image on Cisco switches running as a Smart Install client. The attacker can specify a user account with highest access in the config file, allowing her to take complete control of the switch. The attacker can also upload a custom IOS image with backdoors in it. If the attacker specifies an non-existent image list file or IOS image tar file(s) in the image list file, the IOS image file(s) will not be uploaded. In this case, the attacker-specified config file will still be uploaded to the switch, and that config file will be used as the startup config file on next reboot using the existing IOS image.

Based on testing, the fix in cisco-sa-20130327-smartinstall only addresses the IOS crash/reload caused by malformed content in the image list file. It does not prevent an attacker from uploading an attacker-specified config file to the switch. Moreover, if the attacker specifies a valid IOS image in the image list file, that image will be uploaded and the switch will reboot using that image and the attacker-specified config file.

Note: Tenable asked Cisco to assign a CVE ID on 8/20/2015. An assignment was given to us from Cisco on 8/25/2015 of CVE-2015-6264. When the Cisco advisory was published on 3/23/2016, it used CVE-2016-1349. As such, that is a duplicate assignment and further does not follow CNA standards, as the ID should be issued based on the year it was discovered/reported, not disclosed. MITRE has opted to REJECT CVE-2015-6264 per their policy as CVE-2016-1349 "is the most commonly referenced identifier".

Solution

Cisco has released "free software updates that address the vulnerability". Consult the cisco-sa-20160323-smi advisory for details.

Disclosure Timeline

2015-06-23 - Informed vendor of first issue (RCE) via PSIRT email
2015-06-23 - Vendor acknowledged e-mail. States it is intended functionality, Cisco is looking into adding authentication to feature.
2015-07-02 - Informed vendor of second issue (DoS)
2015-07-02 - Vendor acknowledged e-mail, agrees it is an issue, opened PSIRT-0306179306
2015-08-11 - Pinged vendor on status
2015-08-11 - Vendor confirms fix in works, CSCuv45410 assigned
2015-08-21 - Tenable asks Cisco for CVE assignment, since they are a CNA
2015-08-25 - Cisco assigns CVE for tracking, per Tenable request
2015-11-24 - Tenable pings vendor for update
2015-12-10 - Tenable pings vendor for update
2015-12-10 - Cisco responds, after questioning them about CVE assignments and general security policy re: vulnerability disclosure. Replies saying they are "planning to disclose this through our biannual IOS bundle in March"
2016-03-23 - Vendor releases fix for issue, does not notify Tenable
2016-03-28 - Ping vendor for update
2016-03-28 - Vendor provides link to advisory, showing fix released 2016-03-23

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

Tenable Advisory ID: TRA-2016-04
Credit:
Tenable Network Security
CVSSv2 Base / Temporal Score:
8.3 / 6.5
CVSSv2 Vector:
(AV:A/AC:L/Au:N/C:C/I:C/A:C/E:POC/RL:OF/RC:C)
Affected Products:
Cisco IOS 15.0(2)SE8
Risk Factor:
High
Additional Keywords:
CSCuv45410
CWE-399

Advisory Timeline

2016-03-29 - [R1] Initial release
2016-03-30 - [R2] Add a note about Cisco's duplicate CVE assignment, add 2nd CVE ID

Tenable Vulnerability Management

Formerly Tenable.io

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

Formerly Tenable.io

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

Formerly Tenable.io

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

Formerly Tenable.io

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

Formerly Tenable.io

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

Formerly Tenable.io

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

Formerly Tenable.io Web Application 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

Formerly Tenable.io Web Application 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