Google Pays $250K for a Linux Vulnerability Allowing Guest VM Escape

This week, word emerged of two vulnerabilities in Linux, each of which allows unprivileged users to gain root access on a system.

One of the vulnerabilities is rated high-severity and lets an attacker carry out a guest virtual machine escape — that is, break out of the isolated environment and gain access to the host system. It was for discovering this vulnerability that Google paid the researcher a $250,000 reward as part of its vulnerability bounty program.

The second vulnerability also makes it possible to escalate privileges to root level, though details about its nature and scope are not disclosed in the current reports.

Both issues affect the Linux kernel and are primarily of interest to operators of cloud and virtualized infrastructure, where isolating guest systems from the host is a key element of security. The ability to escape a virtual machine is especially dangerous in multi-tenant environments, where clients from different organizations run simultaneously on a single physical server.

The size of the reward paid out — one of the largest in the history of Google's vulnerability bounty programs — underscores the seriousness of the discovered issue and the importance the company attaches to the security of the open-source components it uses.

The technical details of how the attacks are carried out, as well as information about the release of patches and the timeline for applying them, remain limited as of publication.

Source: Ars Technica