Affected: Cloud Software Group XenServer, Vates XCP-ng

A user with the vm-admin role in XAPI-based hypervisors (XenServer, XCP-ng) can write arbitrary key-value pairs to VDI.sm_config and SR.sm_config. These fields store internal storage driver state including VHD chain metadata, GC control flags, and encryption key hashes. XAPI performs zero validation and never notifies the storage backend. SM drivers consume the attacker's data as authoritative internal state, t…

Affected: Cloud Software Group XenServer, Vates XCP-ng

A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can set VIF.qos_algorithm_params:kbps, which xenopsd writes as a raw Int64.to_string value to the VIF private xenstore path at device.ml:920-927. While Int64.to_string prevents path injection, the raw user-controlled rate values are readable by dom0 processes without provenance tracking. Dom0 tools consuming VIF private xenstore data cannot distinguish betwee…

Affected: Cloud Software Group XenServer, Vates XCP-ng

A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can set VIF.qos_algorithm_params kbps and timeslice_us values that cause Int64 overflow in the bytes_per_interval computation at device.ml:835-845. OCaml silently wraps on integer overflow, producing unexpected rate values. xenopsd bounds checking catches most overflow results, but edge cases where the wrapped value falls within the valid range produce rate l…

Affected: Cloud Software Group XenServer, Vates XCP-ng

A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can set VM.platform:device-model to influence QEMU device model selection. A double whitelist limits impact: XAPI sanity_check (vm_platform.ml:38) validates against known profiles, and xenopsd Profile.of_string resolves to hardcoded binary paths. Unknown values default to Qemu_upstream_compat. The attacker cannot force an arbitrary QEMU binary. Impact is limi…

Affected: Cloud Software Group XenServer, Vates XCP-ng

An attacker with root access on an XAPI-based hypervisor host (XenServer, XCP-ng) can set the expiry key in Host.license_params to never or a far-future date, preventing license expiry enforcement and suppressing alerts. The license_check.ml code reads this value and treats never as no expiration. The field has the strongest XAPI access control (_R_LOCAL_ROOT_ONLY, pool_internal, DynamicRO). This is a license compl…

Affected: Cloud Software Group XenServer, Vates XCP-ng

An attacker with root access on an XAPI-based hypervisor host (XenServer, XCP-ng) can modify the XAPI database to set restrict_* keys in Host.license_params to false, enabling licensed features without a valid license. The field has the strongest access control in XAPI (_R_LOCAL_ROOT_ONLY, pool_internal, DynamicRO) and is not exposed via the network API. This is a license compliance issue - an attacker with root al…

Affected: Cloud Software Group XenServer, Vates XCP-ng

A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can disrupt VM boot by writing an invalid value to VM.HVM_boot_params:firmware or removing the key. XAPI accepts any value at write time but validates at VM start (xapi_xenops.ml:255-268), raising Server_error on invalid values. Firmware key removal causes BIOS fallback, rendering UEFI guests unbootable. The impact is limited because vm-admin already has VM.h…

Affected: Cloud Software Group XenServer, Vates XCP-ng

A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can set an arbitrary boot order string in VM.HVM_boot_params:order. The value is passed verbatim to QEMU as the -boot order argument at device.ml:3957-3958. XAPI performs no validation beyond replacing empty values with the default. QEMU ignores unrecognized characters, limiting impact to forcing PXE network boot when the attacker controls DHCP/PXE infrastruc…

Affected: Cloud Software Group XenServer, Vates XCP-ng

A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can modify VDI.other_config on_boot and cbt_enabled keys without validation. The on_boot key controls VDI reset-on-boot behavior, and cbt_enabled is an other_config mirror of the first-class CBT field read by SM drivers at VDI.py:831-837. Manipulation changes VDI persistence behavior (data loss on reboot) and change block tracking state. The VDI.other_config …

Affected: Cloud Software Group XenServer, Vates XCP-ng

A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can set VBD.other_config polling-duration and polling-idle-threshold to extreme values within the partially validated range. xenopsd applies these as I/O polling parameters without resource impact assessment. The accepted range includes values that produce suboptimal polling configurations, resulting in VBD performance degradation. The VBD.other_config field …