Uncacheable memory on some microprocessors utilizing speculative execution may allow an authenticated user to potentially enable information disclosure via a side channel with local access. Modern Intel microprocessors implement hardware-level micro-optimizations to improve the performance of writing data back to CPU caches. The write operation is split into STA and STD sub-operations. These sub-operations allow the processor to hand-off address generation logic into these sub-operations for optimized writes. Both of these sub-operations write to a shared distributed processor structure called the #039;processor store buffer#039;. As a result, an unprivileged attacker could use this flaw to read private data resident within the CPU#039;s processor store buffer. The virConnectGetDomainCapabilities libvirt API accepts an quot;emulatorbinquot; argument to specify the program providing emulation for a domain. Since v1.2.19, libvirt will execute that program to probe the domain#039;s capabilities. Read-only clients could specify an arbitrary path for this argument, causing libvirtd to execute a crafted executable with its own privileges. It was discovered that libvirtd would permit readonly clients to use the virDomainManagedSaveDefineXML API, which would permit them to modify managed save state files. If a managed save had already been created by a privileged user, a local attacker could modify this file such that libvirtd would execute an arbitrary program when the domain was resumed. A vulnerability was found in libvirt gt;= 4.1.0 in the virtlockd-admin.socket and virtlogd-admin.socket systemd units. A missing SocketMode configuration parameter allows any user on the host to connect using virtlockd-admin-sock or virtlogd-admin-sock and perform administrative tasks against the virtlockd and virtlogd daemons.The virConnectBaselineHypervisorCPU and virConnectCompareHypervisorCPU libvirt APIs accept an quot;emulatorquot; argument to specify the program providing emulation for a domain. Since v1.2.19, libvirt will execute that program to probe the domain#039;s capabilities. Read-only clients could specify an arbitrary path for this argument, causing libvirtd to execute a crafted executable with its own privileges. It was discovered that libvirtd would permit read-only clients to use the virDomainSaveImageGetXMLDesc API, specifying an arbitrary path which would be accessed with the permissions of the libvirtd process. An attacker with access to the libvirtd socket could use this to probe the existence of arbitrary files, cause denial of service or cause libvirtd to execute arbitrary programs. Microprocessors use a load port subcomponent to perform load operations from memory or IO. During a load operation, the load port receives data from the memory or IO subsystem and then provides the data to the CPU registers and operations in the CPUs pipelines. Stale load operations results are stored in the #039;load port#039; table until overwritten by newer operations. Certain load-port operations triggered by an attacker can be used to reveal data about previous stale requests leaking data back to the attacker via a timing side-channel. A flaw was found in the implementation of the quot;fill bufferquot;, a mechanism used by modern CPUs when a cache-miss is made on L1 CPU cache. If an attacker can generate a load operation that would create a page fault, the execution will continue speculatively with incorrect data from the fill buffer while the data is fetched from higher level caches. This response time can be measured to infer data in the fill buffer