Ubuntu Security Notice 5418-1 - Ke Sun, Alyssa Milburn, Henrique Kawakami, Emma Benoit, Igor Chervatyuk, Lisa Aichele, and Thais Moreira Hamasaki discovered that the Spectre Variant 2 mitigations for AMD processors on Linux were insufficient in some situations. A local attacker could possibly use this to expose sensitive information. Demi Marie Obenour and Simon Gaiser discovered that several Xen para- virtualization device frontends did not properly restrict the access rights of device backends. An attacker could possibly use a malicious Xen backend to gain access to memory pages of a guest VM or cause a denial of service in the guest. Continue reading...