Lenovo patches serious vulnerabilities in PC system update tool

The vulnerabilities could allow attackers with access to limited user accounts to gain administrator privileges

For the third time in less than six months security issues have forced Lenovo to update one of the tools preloaded on its PCs.

Last week, the company released version 5.07.0019 of Lenovo System Update, a tool that helps users keep their computers' drivers and BIOS up to date and which was previously called ThinkVantage System Update. The new version fixes two local privilege escalation vulnerabilities discovered by researchers from security firm IOActive.

One of the vulnerabilities is located in the tool's help system and allows users with limited Windows accounts to start an instance of Internet Explorer with administrator privileges by clicking on URLs in help pages. That's because Lenovo System Update itself runs under a temporary administrator account that the application creates when installed, so any process it spawns will run under the same account.

"From there, an unprivileged attacker has many ways to exploit the web browser instance running under Administrator privileges to elevate his or her own privileges to Administrator or SYSTEM," IOActive security researcher Sofiane Talmat said in a blog post Wednesday.

The second vulnerability is also related to the temporary administrator account and particularly to the way in which its name and password are generated.

The username follows the pattern tvsu_tmp_xxxxxXXXXX, where each lowercase x is a randomly generated lower case letter and each uppercase X is a randomly generated uppercase letter. However, the function that's supposed to randomly choose the letters is tied to the current time, making its output predictable.

"It is possible for an attacker to regenerate the same username based on the time the account was created," Talmat said.

The password generation function uses two methods, a secure one and a fallback one that's also predictable. This means that in certain situations an attacker could guess both the username and password and gain administrative privileges.

Lenovo System Update received two other security patches this year: one in July and one in October. Those updates fixed vulnerabilities that could have allowed attackers to execute commands through the application or to replace legitimate updates with malware.

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Lucian Constantin

IDG News Service
Show Comments

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Luke Hill

MSI GT75 TITAN

I need power and lots of it. As a Front End Web developer anything less just won’t cut it which is why the MSI GT75 is an outstanding laptop for me. It’s a sleek and futuristic looking, high quality, beast that has a touch of sci-fi flare about it.

Emily Tyson

MSI GE63 Raider

If you’re looking to invest in your next work horse laptop for work or home use, you can’t go wrong with the MSI GE63.

Laura Johnston

MSI GS65 Stealth Thin

If you can afford the price tag, it is well worth the money. It out performs any other laptop I have tried for gaming, and the transportable design and incredible display also make it ideal for work.

Andrew Teoh

Brother MFC-L9570CDW Multifunction Printer

Touch screen visibility and operation was great and easy to navigate. Each menu and sub-menu was in an understandable order and category

Louise Coady

Brother MFC-L9570CDW Multifunction Printer

The printer was convenient, produced clear and vibrant images and was very easy to use

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Featured Content

Product Launch Showcase

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?