Vulnerability Name:

CVE-2020-29486 (CCN-193135)

Assigned:2020-12-15
Published:2020-12-15
Updated:2021-12-10
Summary:An issue was discovered in Xen through 4.14.x. Nodes in xenstore have an ownership. In oxenstored, a owner could give a node away. However, node ownership has quota implications. Any guest can run another guest out of quota, or create an unbounded number of nodes owned by dom0, thus running xenstored out of memory A malicious guest administrator can cause a denial of service against a specific guest or against the whole host. All systems using oxenstored are vulnerable. Building and using oxenstored is the default in the upstream Xen distribution, if the Ocaml compiler is available. Systems using C xenstored are not vulnerable.
CVSS v3 Severity:6.0 Medium (CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H)
5.2 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:H/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): High
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-770
Vulnerability Consequences:Denial of Service
References:Source: MITRE
Type: CNA
CVE-2020-29486

Source: XF
Type: UNKNOWN
xen-cve202029486-dos(193135)

Source: FEDORA
Type: Mailing List, Third Party Advisory
FEDORA-2020-df772b417b

Source: FEDORA
Type: Mailing List, Third Party Advisory
FEDORA-2020-64859a826b

Source: GENTOO
Type: Third Party Advisory
GLSA-202107-30

Source: DEBIAN
Type: Third Party Advisory
DSA-4812

Source: CCN
Type: Xen Security Advisory XSA-352
oxenstored: node ownership can be changed by unprivileged clients

Source: MISC
Type: Patch, Vendor Advisory
https://xenbits.xenproject.org/xsa/advisory-352.html

Vulnerable Configuration:Configuration 1:
  • cpe:/o:xen:xen:*:*:*:*:*:*:*:* (Version <= 4.14.0)

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

  • Configuration 3:
  • cpe:/o:fedoraproject:fedora:32:*:*:*:*:*:*:*
  • OR cpe:/o:fedoraproject:fedora:33:*:*:*:*:*:*:*

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

  • * Denotes that component is vulnerable
    BACK
    xen xen *
    debian debian linux 10.0
    fedoraproject fedora 32
    fedoraproject fedora 33
    xensource xen *