Synopsis
The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.
Description
The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.
- In the Linux kernel, the following vulnerability has been resolved: KVM: Explicitly verify target vCPU is online in kvm_get_vcpu() Explicitly verify the target vCPU is fully online _prior_ to clamping the index in kvm_get_vcpu(). If the index is bad, the nospec clamping will generate '0', i.e. KVM will return vCPU0 instead of NULL. In practice, the bug is unlikely to cause problems, as it will only come into play if userspace or the guest is buggy or misbehaving, e.g. KVM may send interrupts to vCPU0 instead of dropping them on the floor. However, returning vCPU0 when it shouldn't exist per online_vcpus is problematic now that KVM uses an xarray for the vCPUs array, as KVM needs to insert into the xarray before publishing the vCPU to userspace (see commit c5b077549136 (KVM: Convert the kvm->vcpus array to a xarray)), i.e. before vCPU creation is guaranteed to succeed. As a result, incorrectly providing access to vCPU0 will trigger a use-after-free if vCPU0 is dereferenced and kvm_vm_ioctl_create_vcpu() bails out of vCPU creation due to an error and frees vCPU0. Commit afb2acb2e3a3 (KVM: Fix vcpu_array[0] races) papered over that issue, but in doing so introduced an unsolvable teardown conundrum. Preventing accesses to vCPU0 before it's fully online will allow reverting commit afb2acb2e3a3, without re-introducing the vcpu_array[0] UAF race. (CVE-2024-58083)
Note that Nessus relies on the presence of the package as reported by the vendor.
Solution
There is no known solution at this time.
Plugin Details
File Name: unpatched_CVE_2024_58083.nasl
Agent: unix
Supported Sensors: Nessus Agent, Nessus
Risk Information
Vector: CVSS2#AV:L/AC:M/Au:N/C:P/I:P/A:P
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
Vulnerability Information
Required KB Items: Host/local_checks_enabled, Host/cpu, global_settings/vendor_unpatched
Exploit Ease: No known exploits are available
Vulnerability Publication Date: 3/6/2025