The pygrub boot loader emulator in Xen, when nul-delimited output format is requested, allows local pygrub-using guest OS administrators to read or delete arbitrary files on the host via NUL bytes in the bootloader configuration file.
https://support.citrix.com/article/CTX218775
http://www.securitytracker.com/id/1037347
http://www.securityfocus.com/bid/94473
https://security.gentoo.org/glsa/201612-56
http://xenbits.xen.org/xsa/xsa198.patch
http://xenbits.xen.org/xsa/advisory-198.html
Source: Mitre, NVD
Published: 2017-01-23
Updated: 2025-04-20
Base Score: 4.6
Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:P/A:P
Severity: Medium
Base Score: 7.5
Vector: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N
Severity: High
EPSS: 0.00093