Actively exploited vulnerability
Microsoft Silverlight: information disclosure flaw under attack
CVE-2013-3896 · Microsoft Silverlight Information Disclosure Vulnerability
What is affected
Microsoft Silverlight is found on ordinary personal computers and phones, so this is not only a problem for companies. If you use it and have not updated since the fix was released, you are exposed.
Microsoft Silverlight does not properly validate pointers during access to Silverlight elements, which allows remote attackers to obtain sensitive information via a crafted Silverlight application.
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
- No account needed
- Does the victim have to do something?
- Yes, the victim must open or click something
What to do
- Update Microsoft Silverlight 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.
- Turn on automatic updates so the next fix arrives without you having to look for it.
- If your device is too old to receive this update, stop using the affected app for anything sensitive and plan a replacement.
The impacted product is end-of-life and should be disconnected if still in use.
How urgent is it
CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on May 25, 2022, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by June 15, 2022, 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 68% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 99.3% of all scored vulnerabilities.
Its CVSS severity score is 5.5 out of 10 (medium), as recorded in the US National Vulnerability Database.
Technical description
Microsoft Silverlight 5 before 5.1.20913.0 does not properly validate pointers during access to Silverlight elements, which allows remote attackers to obtain sensitive information via a crafted Silverlight application, aka "Silverlight Vulnerability."