"A Russian security researcher has published details about a zero-day vulnerability affecting VirtualBox, an Oracle software application for running virtual machines," reports ZDNet. According to a text file uploaded on GitHub, Saint Petersburg-based researcher Sergey Zelenyuk has found a chain of bugs that can allow malicious code to escape the VirtualBox virtual machine (the guest OS) and execute on the underlying (host) operating system. Once out of the VirtualBox VM, the malicious code runs in the OS' limited userspace (kernel ring 3), but Zelenyuk said that attackers can use many of the already known privilege escalation bugs to gain kernel-level access (ring 0). "The exploit is 100% reliable," Zelenyuk said. "It means it either works always or never because of mismatched binaries or other, more subtle reasons I didn't account."

The Russian researcher says the zero-day affects all current VirtualBox releases, works regardless of the host or guest operating system the user is running, and is reliable against the default configuration of newly created VMs. Besides a detailed write-up of the entire exploit chain, Zelenyuk has also published video proof, showing the zero-day in action against an Ubuntu VM running inside VirtualBox on an Ubuntu host OS.
Long-time Slashdot reader Artem Tashkinov warns that the exploit utilizes "bugs in the data link layer of the default E1000 network interface adapter which makes this vulnerability critical for everyone who uses virtualization to run untrusted code." According to ZDNet, the same security researcher "found and reported a similar issue in mid-2017, which Oracle took over 15 months to fix."

"This lengthy and drawn-out patching process appears to have angered Zelenyuk, who instead of reporting this bug to Oracle, has decided to publish details online without notifying the vendor."

wiredmikey writes "A new zero-day vulnerability affecting Internet Explorer is being exploited in the wild affecting IE 9 and earlier. The vulnerability, if exploited, would allow full remote code execution and enable an attacker to take over an affected system. Security researcher Eric Romang discovered the vulnerability and exploit over the weekend while monitoring some infected servers said to be used by the alleged Nitro gang. To run the attack, a file named 'exploit.html' is the entry point of the attack ... According to analysis by VUPEN, the exploit takes advantage of a 'use-after-free vulnerability' that affects the mshtml.dll component of Internet Explorer. Rapid7 on Monday released an exploit module for Metaspolit which will let security teams and attackers alike test systems."