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

Apple macOS / iOS UIFoundation Vulnerability

Medium

Synopsis

An issue exists with the NSAttributedString functionality in UIFoundation, particularly when creating objects that abstract the private functionality for NSHTMLReader. When creating NSAttributedString objects containing special formatting for URLs, if it is loaded into a container such as a tableview cell that has not been properly rendered or initialized, the application or service will crash. For example, when NSHTMLReader calls _loadUsingWebkit prior to a tableview cell being fully initialized, the application will crash. As a proof-of-concept, the flaw can be demonstrated locally (safely and recoverable) with the latest version of Notes.app. 1. Open Notes.app 2. Create a new note 3. Copy a URL from a popular web browser or an editor that will copy attributed data to the pasteboard. 4. In the new note, create a table view. 5. In the second row, attempt to paste URL. 6. The application will crash. Please note, Notes.app is being used for demonstration purposes. This is not just a flaw within Notes.app, it is a flaw within UIFoundation. All applications or services using or relying on this functionality are at risk. The primary impact here is a denial of service of the service or application affected, which could result in annoyance, loss of data, or inability to use the application. While the most likely scenario in cases such as this is simply denial-of-service oriented, it is theoretically possible that if developers handle the exception thrown here in some non-default way, other unpredictable circumstances may arise. As we do not have a proof-of-concept for that claim, we've decided to give this a CVSSv2 vector of (AV:N/AC:L/Au:N/C:N/I:N/A). Apple has rejected this bug report as having no security impact. While we understand their point-of-view, we would like to make others aware of the possible issues when developing using this functionality.

Solution

There is no fix available for this issue. We recommend developers rely on other existing functionality in alternative libraries if they are concerned about this issue.

Disclosure Timeline

July 17, 2019 - Initial Discovery.
July 22 2019 - Reported to Apple.
July 30, 2019 - Requested status update.
August 1, 2019 - Apple requests clarification.
August 2, 2019 - Tenable responds needing more information regarding what was unclear.
August 5, 2019 - Apple requests remote PoC.
August 7, 2019 - Tenable states that shouldn't be necessary.
August 8, 2019 - Apple states that this does not appear to have security implications, but will forward it to appropriate team for further investigation.

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-2019-39
Credit:
Pablo Ramos
Jimi Sebree
CVSSv2 Base / Temporal Score:
5.0 / 3.6
CVSSv2 Vector:
AV:N/AC:L/Au:N/C:N/I:N/A:P
Affected Products:
macOS UIFoundation Library
Risk Factor:
Medium

Advisory Timeline

August 12, 2019 - 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