The ssm_i emulation in Xen 5.1 on IA64 architectures allows attackers to cause a denial of service (dom0 panic) via certain traffic, as demonstrated using an FTP stress test tool.

Xen 3.x, possibly before 3.1.2, when running on IA64 systems, does not check the RID value for mov_to_rr, which allows a VTi domain to read memory of other domains.

Xen 3.1.1 does not prevent modification of the CR4 TSC from applications, which allows pv guests to cause a denial of service (crash).

Xen 3.1.1 allows virtual guest system users to cause a denial of service (hypervisor crash) by using a debug register (DR7) to set certain breakpoints.

(1) xenbaked and (2) xenmon.py in Xen 3.1 and earlier allow local users to truncate arbitrary files via a symlink attack on /tmp/xenq-shm.

pygrub (tools/pygrub/src/GrubConf.py) in Xen 3.0.3, when booting a guest domain, allows local users with elevated privileges in the guest domain to execute arbitrary commands in domain 0 via a crafted grub.conf file whose contents are used in exec statements.