#amd

The fwctl driver implements a state machine which is executed when a bhyve guest accesses certain x86 I/O ports. The interface lets the guest copy a string into a buffer resident in the bhyve process' memory. A bug in the state machine implementation can result in a buffer overflowing when copying this string. Malicious, privileged software running in a guest VM can exploit the buffer overflow to achieve code execution on the host in the bhyve userspace process, which typically runs as root, mitigated by the capabilities assigned through the Capsicum sandbox available to the bhyve process.

A set of carefully crafted ipv6 packets can trigger an integer overflow in the calculation of a fragment reassembled packet's payload length field. This allows an attacker to trigger a kernel panic, resulting in a denial of service.

Debian Linux Security Advisory 5462-1 - Tavis Ormandy discovered that under specific microarchitectural circumstances, a vector register in AMD "Zen 2" CPUs may not be written to 0 correctly. This flaw allows an attacker to leak sensitive information across concurrent processes, hyper threads and virtualized guests.

Debian Linux Security Advisory 5461-1 - Several vulnerabilities have been discovered in the Linux kernel that may lead to a privilege escalation, denial of service or information leaks.

Ubuntu Security Notice 6256-1 - Jiasheng Jiang discovered that the HSA Linux kernel driver for AMD Radeon GPU devices did not properly validate memory allocation in certain situations, leading to a null pointer dereference vulnerability. A local attacker could use this to cause a denial of service. Zheng Wang discovered that the Intel i915 graphics driver in the Linux kernel did not properly handle certain error conditions, leading to a double-free. A local attacker could possibly use this to cause a denial of service.

Debian Linux Security Advisory 5459-1 - Tavis Ormandy discovered that under specific microarchitectural circumstances, a vector register in "Zen 2" CPUs may not be written to 0 correctly. This flaw allows an attacker to leak register contents across concurrent processes, hyper threads and virtualized guests.

Ubuntu Security Notice 6244-1 - Tavis Ormandy discovered that some AMD processors did not properly handle speculative execution of certain vector register instructions. A local attacker could use this to expose sensitive information.

A new security vulnerability has been discovered in AMD's Zen 2 architecture-based processors that could be exploited to extract sensitive data such as encryption keys and passwords. Discovered by Google Project Zero researcher Tavis Ormandy, the flaw – codenamed Zenbleed and tracked as CVE-2023-20593 (CVSS score: 6.5) – allows data exfiltration at the rate of 30 kb per core, per second. The

The PKCS#11 feature in ssh-agent in OpenSSH versions prior to 9.3p2 has an insufficiently trustworthy search path, leading to remote code execution if an agent is forwarded to an attacker-controlled system.

Based on Kata Containers, the Confidential Containers (CoCo) project is a community solution to enable hardware technologies for virtualized memory encryption in container environments through attestation. CoCo SEV enables an encrypted container launch feature by utilizing a remote key broker service to verify the guest measured environment before releasing the image decryption key during orchestration. This blog demonstrates how to prepare an EPYC™ CPU-powered machine for SEV and CoCo, how to install CoCo using a Kubernetes operator, and how to create an encrypted image and start a containe