Xen Orchestra: any authenticated user reaches global admin through unprotected ESXi import methods

Impact

The ESXi import API methods carried no permission check, so any account that can log in to Xen Orchestra can point xo-server at an attacker-controlled ESXi host. A crafted .vmx file setting __proto__.permission pollutes Object.prototype, which hands permission-less accounts administrator rights across the whole Xen Orchestra instance and from there remote code execution. For an operator running virtualized GPU hosts under XCP-ng/Xen, that is full control of the virtualization management plane: VM creation and deletion, console access, storage and backup configuration across every pool the instance manages. A low-value read-only account becomes fleet-wide control.

Who can reach it

Any authenticated Xen Orchestra user, including one with no permissions, who can reach the xo-server API over the network. The server must also be able to make an outbound connection to the host the attacker names.

What to do

Upgrade Xen Orchestra to 6.9.0 or later and restart xo-server. Until then, treat every existing XO account as potentially administrative: review the user list, rotate credentials and audit recent actions, and block xo-server outbound access to untrusted hosts. The management interface should not be exposed beyond the operations network.

References

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