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nessusThis script is Copyright (C) 2022-2023 and is owned by Tenable, Inc. or an Affiliate thereof.EULEROS_SA-2022-1440.NASL
HistoryApr 18, 2022 - 12:00 a.m.

EulerOS 2.0 SP9 : util-linux (EulerOS-SA-2022-1440)

2022-04-1800:00:00
This script is Copyright (C) 2022-2023 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
17
euleros
util-linux
libmount
unprivileged user
fuse filesystem
denial of service
cve-2021-3996
cve-2021-3995

CVSS3

5.5

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

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

AI Score

6

Confidence

High

EPSS

0

Percentile

5.1%

According to the versions of the util-linux packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  • A logic error was found in the libmount library of util-linux in the function that allows an unprivileged user to unmount a FUSE filesystem. This flaw allows a local user on a vulnerable system to unmount other users’ filesystems that are either world-writable themselves (like /tmp) or mounted in a world-writable directory. An attacker may use this flaw to cause a denial of service to applications that use the affected filesystems. (CVE-2021-3996)

  • A logic error was found in the libmount library of util-linux in the function that allows an unprivileged user to unmount a FUSE filesystem. This flaw allows an unprivileged local attacker to unmount FUSE filesystems that belong to certain other users who have a UID that is a prefix of the UID of the attacker in its string form. An attacker may use this flaw to cause a denial of service to applications that use the affected filesystems. (CVE-2021-3995)

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

#%NASL_MIN_LEVEL 70300
##
# (C) Tenable, Inc.
##

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(159780);
  script_version("1.6");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/11/01");

  script_cve_id("CVE-2021-3995", "CVE-2021-3996");

  script_name(english:"EulerOS 2.0 SP9 : util-linux (EulerOS-SA-2022-1440)");

  script_set_attribute(attribute:"synopsis", value:
"The remote EulerOS host is missing multiple security updates.");
  script_set_attribute(attribute:"description", value:
"According to the versions of the util-linux packages installed, the EulerOS installation on the remote host is affected
by the following vulnerabilities :

  - A logic error was found in the libmount library of util-linux in the function that allows an unprivileged
    user to unmount a FUSE filesystem. This flaw allows a local user on a vulnerable system to unmount other
    users' filesystems that are either world-writable themselves (like /tmp) or mounted in a world-writable
    directory. An attacker may use this flaw to cause a denial of service to applications that use the
    affected filesystems. (CVE-2021-3996)

  - A logic error was found in the libmount library of util-linux in the function that allows an unprivileged
    user to unmount a FUSE filesystem. This flaw allows an unprivileged local attacker to unmount FUSE
    filesystems that belong to certain other users who have a UID that is a prefix of the UID of the attacker
    in its string form. An attacker may use this flaw to cause a denial of service to applications that use
    the affected filesystems. (CVE-2021-3995)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security
advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional
issues.");
  # https://developer.huaweicloud.com/ict/en/site-euleros/euleros/security-advisories/EulerOS-SA-2022-1440
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?5c64f2b0");
  script_set_attribute(attribute:"solution", value:
"Update the affected util-linux packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:N/I:N/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-3996");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2022/04/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2022/04/18");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/04/18");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:libblkid");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:libfdisk");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:libmount");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:libsmartcols");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:libuuid");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:util-linux");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:util-linux-user");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:2.0");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2022-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/cpu", "Host/EulerOS/release", "Host/EulerOS/rpm-list", "Host/EulerOS/sp");
  script_exclude_keys("Host/EulerOS/uvp_version");

  exit(0);
}

include("rpm.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);

var release = get_kb_item("Host/EulerOS/release");
if (isnull(release) || release !~ "^EulerOS") audit(AUDIT_OS_NOT, "EulerOS");
var uvp = get_kb_item("Host/EulerOS/uvp_version");
if (release !~ "^EulerOS release 2\.0(\D|$)") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP9");

var sp = get_kb_item("Host/EulerOS/sp");
if (isnull(sp) || sp !~ "^(9)$") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP9");

if (!empty_or_null(uvp)) audit(AUDIT_OS_NOT, "EulerOS 2.0 SP9", "EulerOS UVP " + uvp);

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

var cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "aarch64" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "EulerOS", cpu);
if ("aarch64" >!< cpu) audit(AUDIT_ARCH_NOT, "aarch64", cpu);

var flag = 0;

var pkgs = [
  "libblkid-2.35.1-1.h24.eulerosv2r9",
  "libfdisk-2.35.1-1.h24.eulerosv2r9",
  "libmount-2.35.1-1.h24.eulerosv2r9",
  "libsmartcols-2.35.1-1.h24.eulerosv2r9",
  "libuuid-2.35.1-1.h24.eulerosv2r9",
  "util-linux-2.35.1-1.h24.eulerosv2r9",
  "util-linux-user-2.35.1-1.h24.eulerosv2r9"
];

foreach (var pkg in pkgs)
  if (rpm_check(release:"EulerOS-2.0", sp:"9", reference:pkg)) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "util-linux");
}

CVSS3

5.5

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

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

AI Score

6

Confidence

High

EPSS

0

Percentile

5.1%