Actively exploited vulnerability
Oracle VirtualBox: improper access control flaw under attack
CVE-2008-3431 · Oracle VirtualBox Insufficient Input Validation Vulnerability
What is affected
Oracle VirtualBox is mostly run by companies, schools and public bodies, not on home computers. You are unlikely to have it yourself, but organisations that hold your data may. Breaches that start with flaws like this one are how personal data ends up leaked.
An input validation vulnerability exists in the VBoxDrv.sys driver of Sun xVM VirtualBox which allows attackers to locally execute arbitrary code.
What an attacker can do
This is a improper access control flaw. It lets an attacker perform actions or reach data that should be restricted to authorised users.
- 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
- At home: nothing to install. Keep your own devices updated and use a different password for every service, so that a breach at one organisation does not open your other accounts.
- If you administer Oracle VirtualBox at work: apply the vendor's fix or mitigation now and review logs for signs of compromise, because the flaw was being exploited before it was listed.
- If the product is past its support date and no fix exists, take it off the internet or retire it.
Apply updates per vendor instructions.
How urgent is it
CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on March 3, 2022, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by March 24, 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 6.9% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 94% of all scored vulnerabilities.
Its CVSS severity score is 8.8 out of 10 (high), as recorded in the US National Vulnerability Database.
Technical description
The VBoxDrvNtDeviceControl function in VBoxDrv.sys in Sun xVM VirtualBox before 1.6.4 uses the METHOD_NEITHER communication method for IOCTLs and does not properly validate a buffer associated with the Irp object, which allows local users to gain privileges by opening the \\.\VBoxDrv device and calling DeviceIoControl to send a crafted kernel address.