CVE-2021-28701

high
New! CVE Severity Now Using CVSS v3

The calculated severity for CVEs has been updated to use CVSS v3 by default. CVEs that do not have a CVSS v3 score will fall back CVSS v2 for calculating severity. Severity display preferences can be toggled in the settings dropdown.

Description

Another race in XENMAPSPACE_grant_table handling Guests are permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, are de-allocated when a guest switches (back) from v2 to v1. Freeing such pages requires that the hypervisor enforce that no parallel request can result in the addition of a mapping of such a page to a guest. That enforcement was missing, allowing guests to retain access to pages that were freed and perhaps re-used for other purposes. Unfortunately, when XSA-379 was being prepared, this similar issue was not noticed.

References

https://xenbits.xenproject.org/xsa/advisory-384.txt

http://xenbits.xen.org/xsa/advisory-384.html

http://www.openwall.com/lists/oss-security/2021/09/08/2

https://lists.fedoraproject.org/archives/list/[email protected]/message/L4MI3MQAPGILCLXBGQWPZHGE3ALSO4ZU/

https://lists.fedoraproject.org/archives/list/[email protected]/message/CEHZLIR5DFYYQBH55AERWHLO54OFU42C/

https://www.debian.org/security/2021/dsa-4977

https://lists.fedoraproject.org/archives/list/[email protected]/message/3HEHUIUWSSMCQGQY3GWX4J2SZGYP5W2Z/

Details

Source: MITRE

Published: 2021-09-08

Updated: 2021-09-25

Type: CWE-269

Risk Information

CVSS v2

Base Score: 4.4

Vector: AV:L/AC:M/Au:N/C:P/I:P/A:P

Impact Score: 6.4

Exploitability Score: 3.4

Severity: MEDIUM

CVSS v3

Base Score: 7.8

Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

Impact Score: 6

Exploitability Score: 1.1

Severity: HIGH

Vulnerable Software

Configuration 1

OR

cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:*

Tenable Plugins

View all (9 total)

IDNameProductFamilySeverity
154015OracleVM 3.4 : xen (OVMSA-2021-0033)NessusOracleVM Local Security Checks
high
153951SUSE SLES12 Security Update : xen (SUSE-SU-2021:3322-1)NessusSuSE Local Security Checks
high
153615SUSE SLES12 Security Update : xen (SUSE-SU-2021:3213-1)NessusSuSE Local Security Checks
high
153538SUSE SLED12 / SLES12 Security Update : xen (SUSE-SU-2021:3181-1)NessusSuSE Local Security Checks
high
153529openSUSE 15 Security Update : xen (openSUSE-SU-2021:1301-1)NessusSuSE Local Security Checks
high
153509Debian DSA-4977-1 : xen - security updateNessusDebian Local Security Checks
high
153483SUSE SLED15 / SLES15 Security Update : xen (SUSE-SU-2021:3141-1)NessusSuSE Local Security Checks
high
153479openSUSE 15 Security Update : xen (openSUSE-SU-2021:3140-1)NessusSuSE Local Security Checks
high
153478SUSE SLED15 / SLES15 Security Update : xen (SUSE-SU-2021:3140-1)NessusSuSE Local Security Checks
high