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nessusThis script is Copyright (C) 2020-2024 and is owned by Tenable, Inc. or an Affiliate thereof.FEDORA_2020-6DD36A716C.NASL
HistoryNov 20, 2020 - 12:00 a.m.

Fedora 31 : xen (2020-6dd36a716c)

2020-11-2000:00:00
This script is Copyright (C) 2020-2024 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
28

CVSS2

6.9

Attack Vector

LOCAL

Attack Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

COMPLETE

Integrity Impact

COMPLETE

Availability Impact

COMPLETE

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

CVSS3

7.8

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

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

AI Score

6.6

Confidence

High

EPSS

0.001

Percentile

17.6%

revised patch for XSA-286 (mitigating performance impact)


x86 PV guest INVLPG-like flushes may leave stale TLB entries [XSA-286, CVE-2020-27674] (#1891092)


x86: Race condition in Xen mapping code [XSA-345] undue deferral of IOMMU TLB flushes [XSA-346] unsafe AMD IOMMU page table updates [XSA-347]

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Fedora Security Advisory FEDORA-2020-6dd36a716c.
#

include('compat.inc');

if (description)
{
  script_id(143135);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/02/08");

  script_cve_id(
    "CVE-2020-27670",
    "CVE-2020-27671",
    "CVE-2020-27672",
    "CVE-2020-27674"
  );
  script_xref(name:"FEDORA", value:"2020-6dd36a716c");

  script_name(english:"Fedora 31 : xen (2020-6dd36a716c)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Fedora host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"revised patch for XSA-286 (mitigating performance impact)

----

x86 PV guest INVLPG-like flushes may leave stale TLB entries [XSA-286,
CVE-2020-27674] (#1891092)

----

x86: Race condition in Xen mapping code [XSA-345] undue deferral of
IOMMU TLB flushes [XSA-346] unsafe AMD IOMMU page table updates
[XSA-347]

Note that Tenable Network Security has extracted the preceding
description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as
possible without introducing additional issues.");
  script_set_attribute(attribute:"see_also", value:"https://bodhi.fedoraproject.org/updates/FEDORA-2020-6dd36a716c");
  script_set_attribute(attribute:"solution", value:
"Update the affected xen package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:M/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-27672");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2020-27671");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/10/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/11/20");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/11/20");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:xen");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:31");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Fedora Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2020-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list");

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("rpm.inc");


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/RedHat/release");
if (isnull(release) || "Fedora" >!< release) audit(AUDIT_OS_NOT, "Fedora");
os_ver = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora");
os_ver = os_ver[1];
if (! preg(pattern:"^31([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 31", "Fedora " + os_ver);

if (!get_kb_item("Host/RedHat/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);


cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Fedora", cpu);


flag = 0;
if (rpm_check(release:"FC31", reference:"xen-4.12.3-8.fc31")) flag++;


if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "xen");
}
VendorProductVersionCPE
fedoraprojectfedoraxenp-cpe:/a:fedoraproject:fedora:xen
fedoraprojectfedora31cpe:/o:fedoraproject:fedora:31

CVSS2

6.9

Attack Vector

LOCAL

Attack Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

COMPLETE

Integrity Impact

COMPLETE

Availability Impact

COMPLETE

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

CVSS3

7.8

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

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

AI Score

6.6

Confidence

High

EPSS

0.001

Percentile

17.6%