The pyGrub boot loader in Xen 3.0.3, 3.3.0, and Xen-3.3.1 does not support the password option in grub.conf for para-virtualized guests, which allows attackers with access to the para-virtualized guest console to boot the guest or modify the guest's kernel boot parameters without providing the expected password.

The hypervisor_callback function in Xen, possibly before 3.4.0, as applied to the Linux kernel 2.6.30-rc4, 2.6.18, and probably other versions allows guest user applications to cause a denial of service (kernel oops) of the guest OS by triggering a segmentation fault in "certain address ranges."

xend in Xen 3.0.3 does not properly limit the contents of the /local/domain xenstore directory tree, and does not properly restrict a guest VM's write access within this tree, which allows guest OS users to cause a denial of service and possibly have unspecified other impact by writing to (1) console/tty, (2) console/limit, or (3) image/device-model-pid. NOTE: this issue was originally reported as an issue in libvirt 0.3.3 and xenstore, but CVE is considering the core issue to be related to Xen.

Buffer overflow in the backend framebuffer of XenSource Xen Para-Virtualized Framebuffer (PVFB) Message 3.0 through 3.0.3 allows local users to cause a denial of service (SDL crash) and possibly execute arbitrary code via "bogus screen updates," related to missing validation of the "format of messages."

Buffer overflow in the backend of XenSource Xen Para Virtualized Frame Buffer (PVFB) 3.0 through 3.1.2 allows local users to cause a denial of service (crash) and possibly execute arbitrary code via a crafted description of a shared framebuffer.

(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.