Samsung Mobile Devices: information disclosure flaw under attack

What is affected

Samsung Mobile Devices are found on ordinary personal computers and phones, so this is not only a problem for companies. If you use them and have not updated since the fix was released, you are exposed.

Samsung mobile devices contain an out-of-bounds read vulnerability within the modem interface driver due to a lack of boundary checking of a buffer in set_skb_priv(), leading to remote code execution by dereference of an invalid function pointer.

What an attacker can do

This is a information disclosure flaw. It lets an attacker read data they are not supposed to see, such as memory contents, credentials or internal files. It is often the first step of a larger attack.

How it is reached

Needs access to the device or a file opened on it

Access the attacker needs

A basic user account

Does the victim have to do something?

No, works without the victim doing anything

What to do

1. Update Samsung Mobile Devices now. Open the update or "About" screen, install whatever is offered and restart the app or device, because the fix is not active until you do.
2. Turn on automatic updates so the next fix arrives without you having to look for it.
3. If your device is too old to receive this update, stop using the affected app for anything sensitive and plan a replacement.

Apply updates per vendor instructions or discontinue use of the product if updates are unavailable

Vendor advisories and fixes

• security.samsungmobile.comsecurity.samsungmobile.com/securityUpdate.smsb?year=2021&month=10

How urgent is it

CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on June 29, 2023, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by July 20, 2023, a deadline that has already passed. That deadline does not bind anyone else, but it shows how seriously the agency rates it.

The EPSS model estimates a 0.6% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 49% of all scored vulnerabilities.

Its CVSS severity score is 7.8 out of 10 (high), as recorded in the US National Vulnerability Database.

Technical description

Lack of boundary checking of a buffer in set_skb_priv() of modem interface driver prior to SMR Oct-2021 Release 1 allows OOB read and it results in arbitrary code execution by dereference of invalid function pointer.