Red Hat libvirt

libvirt before 2.0.0 improperly disables password checking when the password on a VNC server is set to an empty string, which allows remote attackers to bypass authentication and establish a VNC session by connecting to the server.

A vulnerability was found in libvirt >= 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, 4.x.x before 4.10.1 and 5.x.x before 5.4.1, accept an "emulator" argument to specify the program providing emulation for a domain. Since v1.2.19, libvirt will execute that program to probe the domain's capabilities. Read-only clients could specify an arbitrary path for this argument, causing libvirtd to execute a crafted executable with its own privileges.

The virConnectGetDomainCapabilities() libvirt API, versions 4.x.x before 4.10.1 and 5.x.x before 5.4.1, accepts an "emulatorbin" argument to specify the program providing emulation for a domain. Since v1.2.19, libvirt will execute that program to probe the domain'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 before versions 4.10.1 and 5.4.1 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.

A flaw was found in libvirt, where it leaked a file descriptor for `/dev/mapper/control` into the QEMU process. This file descriptor allows for privileged operations to happen against the device-mapper on the host. This flaw allows a malicious guest user or process to perform operations outside of their standard permissions, potentially causing serious damage to the host operating system. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.

The virConnectDomainXMLToNative API function in libvirt 1.1.0 through 1.1.3 checks for the connect:read permission instead of the connect:write permission, which allows attackers to gain domain:write privileges and execute Qemu binaries via crafted XML. NOTE: some of these details are obtained from third party information.

libvirt version 2.3.0 and later is vulnerable to a bad default configuration of "verify-peer=no" passed to QEMU by libvirt resulting in a failure to validate SSL/TLS certificates by default.

It was discovered that libvirtd, versions 4.x.x before 4.10.1 and 5.x.x before 5.4.1, 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.

util/virlog.c in libvirt does not properly determine the hostname on LXC container startup, which allows local guest OS users to bypass an intended container protection mechanism and execute arbitrary commands via a crafted NSS module.

A NULL pointer deference flaw was found in the way libvirt from 2.5.0 to 3.0.0 handled empty drives. A remote authenticated attacker could use this flaw to crash libvirtd daemon resulting in denial of service.

qemu/qemu_monitor.c in libvirt allows attackers to cause a denial of service (memory consumption) via a large QEMU reply.

libvirt version before 4.2.0-rc1 is vulnerable to a resource exhaustion as a result of an incomplete fix for CVE-2018-5748 that affects QEMU monitor but now also triggered via QEMU guest agent.

libvirt-domain.c in libvirt before 1.3.1 supports virDomainGetTime API calls by guest agents with an RO connection, even though an RW connection was supposed to be required, a different vulnerability than CVE-2019-3886.

A double free memory issue was found to occur in the libvirt API, in versions before 6.8.0, responsible for requesting information about network interfaces of a running QEMU domain. This flaw affects the polkit access control driver. Specifically, clients connecting to the read-write socket with limited ACL permissions could use this flaw to crash the libvirt daemon, resulting in a denial of service, or potentially escalate their privileges on the system. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

virt-login-shell in libvirt 1.1.2 through 1.1.3 allows local users to overwrite arbitrary files and possibly gain privileges via unspecified environment variables or command-line arguments.

libvirt.c in the API in Red Hat libvirt 0.8.8 does not properly restrict operations in a read-only connection, which allows remote attackers to cause a denial of service (host OS crash) or possibly execute arbitrary code via a (1) virNodeDeviceDettach, (2) virNodeDeviceReset, (3) virDomainRevertToSnapshot, (4) virDomainSnapshotDelete, (5) virNodeDeviceReAttach, or (6) virConnectDomainXMLToNative call, a different vulnerability than CVE-2008-5086.

The virSecurityManagerSetProcessLabel function in libvirt 0.10.2.7, 1.0.5.5, and 1.1.1, when the domain has read an uid:gid label, does not properly set group memberships, which allows local users to gain privileges.

Use-after-free vulnerability in the virNetMessageFree function in rpc/virnetserverclient.c in libvirt 1.0.x before 1.0.2, 0.10.2 before 0.10.2.3, 0.9.11 before 0.9.11.9, and 0.9.6 before 0.9.6.4 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code by triggering certain errors during an RPC connection, which causes a message to be freed without being removed from the message queue.

Multiple race conditions in the (1) virDomainBlockStats, (2) virDomainGetBlockInf, (3) qemuDomainBlockJobImpl, and (4) virDomainGetBlockIoTune functions in libvirt before 1.2.1 do not properly verify that the disk is attached, which allows remote read-only attackers to cause a denial of service (libvirtd crash) via the virDomainDetachDeviceFlags command.

A NULL pointer dereference was found in the libvirt API responsible introduced in upstream version 3.10.0, and fixed in libvirt 6.0.0, for fetching a storage pool based on its target path. In more detail, this flaw affects storage pools created without a target path such as network-based pools like gluster and RBD. Unprivileged users with a read-only connection could abuse this flaw to crash the libvirt daemon, resulting in a potential denial of service.

An issue was discovered in qemuDomainGetStatsIOThread in qemu/qemu_driver.c in libvirt 4.10.0 though 6.x before 6.1.0. A memory leak was found in the virDomainListGetStats libvirt API that is responsible for retrieving domain statistics when managing QEMU guests. This flaw allows unprivileged users with a read-only connection to cause a memory leak in the domstats command, resulting in a potential denial of service.

A use-after-free flaw was found in libvirt. The qemuMonitorUnregister() function in qemuProcessHandleMonitorEOF is called using multiple threads without being adequately protected by a monitor lock. This flaw could be triggered by the virConnectGetAllDomainStats API when the guest is shutting down. An unprivileged client with a read-only connection could use this flaw to perform a denial of service attack by causing the libvirt daemon to crash.

The virStorageVolCreateXML API in libvirt 1.2.14 through 1.2.19 allows remote authenticated users with a read-write connection to cause a denial of service (libvirtd crash) by triggering a failed unlink after creating a volume on a root_squash NFS pool.

An improper locking issue was found in the virStoragePoolLookupByTargetPath API of libvirt. It occurs in the storagePoolLookupByTargetPath function where a locked virStoragePoolObj object is not properly released on ACL permission failure. Clients connecting to the read-write socket with limited ACL permissions could use this flaw to acquire the lock and prevent other users from accessing storage pool/volume APIs, resulting in a denial of service condition. The highest threat from this vulnerability is to system availability.

An information disclosure vulnerability was found in libvirt in versions before 6.3.0. HTTP cookies used to access network-based disks were saved in the XML dump of the guest domain. This flaw allows an attacker to access potentially sensitive information in the domain configuration via the `dumpxml` command.

A flaw was found in libvirt in the virConnectListAllNodeDevices API in versions before 7.0.0. It only affects hosts with a PCI device and driver that supports mediated devices (e.g., GRID driver). This flaw could be used by an unprivileged client with a read-only connection to crash the libvirt daemon by executing the 'nodedev-list' virsh command. The highest threat from this vulnerability is to system availability.

A missing authorization flaw was found in the libvirt API responsible for changing the QEMU agent response timeout. This flaw allows read-only connections to adjust the time that libvirt waits for the QEMU guest agent to respond to agent commands. Depending on the timeout value that is set, this flaw can make guest agent commands fail because the agent cannot respond in time. Unprivileged users with a read-only connection could abuse this flaw to set the response timeout for all guest agent messages to zero, potentially leading to a denial of service. This flaw affects libvirt versions before 6.2.0.

Libvirt: improper locking in virstoragepoolobjlistsearch may lead to denial of service

The qemu implementation in libvirt before 1.3.0 and Xen allows local guest OS users to cause a denial of service (host disk consumption) by writing to stdout or stderr.

A flaw was found in the libvirt libxl driver. A malicious guest could continuously reboot itself and cause libvirtd on the host to deadlock or crash, resulting in a denial of service condition.

A NULL pointer dereference flaw was discovered in libvirt before version 5.0.0 in the way it gets interface information through the QEMU agent. An attacker in a guest VM can use this flaw to crash libvirtd and cause a denial of service.

A flaw was found in libvirt while it generates SELinux MCS category pairs for VMs' dynamic labels. This flaw allows one exploited guest to access files labeled for another guest, resulting in the breaking out of sVirt confinement. The highest threat from this vulnerability is to confidentiality and integrity.

Libvirt: crash of virtinterfaced via virconnectlistinterfaces()

The networkReloadIptablesRules function in network/bridge_driver.c in libvirt before 0.9.9 does not properly handle firewall rules on bridge networks when libvirtd is restarted, which might allow remote attackers to bypass intended access restrictions via a (1) DNS or (2) DHCP query.

The LXC driver (lxc/lxc_driver.c) in libvirt 1.0.1 through 1.2.1 allows local users to (1) delete arbitrary host devices via the virDomainDeviceDettach API and a symlink attack on /dev in the container; (2) create arbitrary nodes (mknod) via the virDomainDeviceAttach API and a symlink attack on /dev in the container; and cause a denial of service (shutdown or reboot host OS) via the (3) virDomainShutdown or (4) virDomainReboot API and a symlink attack on /dev/initctl in the container, related to "paths under /proc/$PID/root" and the virInitctlSetRunLevel function.

qemu/qemu_driver.c in libvirt before 6.0.0 mishandles the holding of a monitor job during a query to a guest agent, which allows attackers to cause a denial of service (API blockage).

A vulnerability was found in libvirt. This security flaw ouccers due to repeatedly querying an SR-IOV PCI device's capabilities that exposes a memory leak caused by a failure to free the virPCIVirtualFunction array within the parent struct's g_autoptr cleanup.

Libvirt: null pointer dereference in udevconnectlistallinterfaces()

An incorrect permissions check was discovered in libvirt 4.8.0 and above. The readonly permission was allowed to invoke APIs depending on the guest agent, which could lead to potentially disclosing unintended information or denial of service by causing libvirt to block.