Vulnerability Name:

CVE-2020-15564 (CCN-184662)

Assigned:2020-07-07
Published:2020-07-07
Updated:2022-05-03
Summary:An issue was discovered in Xen through 4.13.x, allowing Arm guest OS users to cause a hypervisor crash because of a missing alignment check in VCPUOP_register_vcpu_info. The hypercall VCPUOP_register_vcpu_info is used by a guest to register a shared region with the hypervisor. The region will be mapped into Xen address space so it can be directly accessed. On Arm, the region is accessed with instructions that require a specific alignment. Unfortunately, there is no check that the address provided by the guest will be correctly aligned. As a result, a malicious guest could cause a hypervisor crash by passing a misaligned address. A malicious guest administrator may cause a hypervisor crash, resulting in a Denial of Service (DoS). All Xen versions are vulnerable. Only Arm systems are vulnerable. x86 systems are not affected.
CVSS v3 Severity:6.5 Medium (CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H)
5.7 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope:Scope (S): Changed
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): High
4.4 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H)
3.9 Low (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): High
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): High
CVSS v2 Severity:4.9 Medium (CVSS v2 Vector: AV:L/AC:L/Au:N/C:N/I:N/A:C)
Exploitability Metrics:Access Vector (AV): Local
Access Complexity (AC): Low
Authentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Complete
4.6 Medium (CCN CVSS v2 Vector: AV:L/AC:L/Au:S/C:N/I:N/A:C)
Exploitability Metrics:Access Vector (AV): Local
Access Complexity (AC): Low
Athentication (Au): Single_Instance
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Complete
Vulnerability Type:CWE-119
Vulnerability Consequences:Denial of Service
References:Source: MITRE
Type: CNA
CVE-2020-15564

Source: MLIST
Type: Mailing List, Patch, Third Party Advisory
[oss-security] 20200707 Xen Security Advisory 327 v3 (CVE-2020-15564) - Missing alignment check in VCPUOP_register_vcpu_info

Source: CCN
Type: Xen Security Advisory XSA-327
Missing alignment check in VCPUOP_register_vcpu_info

Source: MISC
Type: Patch, Third Party Advisory
http://xenbits.xen.org/xsa/advisory-327.html

Source: XF
Type: UNKNOWN
xen-cve202015564-dos(184662)

Source: FEDORA
Type: Mailing List, Third Party Advisory
FEDORA-2020-76cf2b0f0a

Source: FEDORA
Type: Mailing List, Third Party Advisory
FEDORA-2020-fbc13516af

Source: GENTOO
Type: Third Party Advisory
GLSA-202007-02

Source: DEBIAN
Type: Third Party Advisory
DSA-4723

Vulnerable Configuration:Configuration 1:
  • cpe:/o:xen:xen:*:*:*:*:*:*:arm:* (Version >= 4.8.0 and <= 4.13.1)

    • Configuration 2:
  • cpe:/o:debian:debian_linux:10.0:*:*:*:*:*:*:*

    • Configuration 3:
  • cpe:/o:fedoraproject:fedora:31:*:*:*:*:*:*:*
  • OR cpe:/o:fedoraproject:fedora:32:*:*:*:*:*:*:*

    • Configuration CCN 1:
  • cpe:/a:xensource:xen:*:*:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    BACK
    xen xen *
    debian debian linux 10.0
    fedoraproject fedora 31
    fedoraproject fedora 32
    xensource xen *