CVE-2017-12855
Xen maintains the _GTF_{read,writ}ing bits as appropriate, to inform the guest that a grant is in use.
Does this matter?
Lower severity and a low EPSS score (0.40%). Track it; it rarely justifies an emergency change on its own.
Description
Xen maintains the _GTF_{read,writ}ing bits as appropriate, to inform the guest that a grant is in use. A guest is expected not to modify the grant details while it is in use, whereas the guest is free to modify/reuse the grant entry when it is not in use. Under some circumstances, Xen will clear the status bits too early, incorrectly informing the guest that the grant is no longer in use. A guest may prematurely believe that a granted frame is safely private again, and reuse it in a way which contains sensitive information, while the domain on the far end of the grant is still using the grant. Xen 4.9, 4.8, 4.7, 4.6, and 4.5 are affected.
- CVSS 3.0
- 6.5 MEDIUMCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
- EPSS
- 0.40% probability · 34th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-200
- Affected
- xen/xen
- Source
- cve@mitre.org
EPSS 0.4% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://www.debian.org/security/2017/dsa-3969
- http://www.securityfocus.com/bid/100341Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1039177Third Party Advisory, VDB Entry
- http://xenbits.xen.org/xsa/advisory-230.htmlVendor Advisory
- https://support.citrix.com/article/CTX225941
- http://www.debian.org/security/2017/dsa-3969
- http://www.securityfocus.com/bid/100341Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1039177Third Party Advisory, VDB Entry
- http://xenbits.xen.org/xsa/advisory-230.htmlVendor Advisory
- https://support.citrix.com/article/CTX225941
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.