| Summary | A PV guest could DoS Xen while unmapping a grant To address XSA-380, reference counting was introduced for grant mappings for the case where a PV guest would have the IOMMU enabled. PV guests can request two forms of mappings. When both are in use for any individual mapping, unmapping of such a mapping can be requested in two steps. The reference count for such a mapping would then mistakenly be decremented twice. Underflow of the counters gets detected, resulting in the triggering of a hypervisor bug check. |
|---|---|
| Publication Date | Jan. 25, 2022, 11:15 p.m. |
| Registration Date | Jan. 26, 2022, 10 a.m. |
| Last Update | Nov. 21, 2024, 3:47 p.m. |
| CVSS3.1 : MEDIUM | |
| スコア | 5.5 |
|---|---|
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| 攻撃元区分(AV) | ローカル |
| 攻撃条件の複雑さ(AC) | 低 |
| 攻撃に必要な特権レベル(PR) | 低 |
| 利用者の関与(UI) | 不要 |
| 影響の想定範囲(S) | 変更なし |
| 機密性への影響(C) | なし |
| 完全性への影響(I) | なし |
| 可用性への影響(A) | 高 |
| CVSS2.0 : LOW | |
| Score | 2.1 |
|---|---|
| Vector | AV:L/AC:L/Au:N/C:N/I:N/A:P |
| 攻撃元区分(AV) | ローカル |
| 攻撃条件の複雑さ(AC) | 低 |
| 攻撃前の認証要否(Au) | 不要 |
| 機密性への影響(C) | なし |
| 完全性への影響(I) | なし |
| 可用性への影響(A) | 低 |
| Get all privileges. | いいえ |
| Get user privileges | いいえ |
| Get other privileges | いいえ |
| User operation required | いいえ |
| Configuration1 | or higher | or less | more than | less than | |
| cpe:2.3:o:xen:xen:*:*:*:*:*:*:x86:* | 3.2.0 | 4.13.0 | |||
| Configuration2 | or higher | or less | more than | less than | |
| cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* | |||||
| Configuration3 | or higher | or less | more than | less than | |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | |||||
| cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* | |||||