EulerOS Virtualization 3.0.2.2 : openssh (EulerOS-SA-2021-2153)

2021-07-06T00:00:00
ID EULEROS_SA-2021-2153.NASL
Type nessus
Reporter This script is Copyright (C) 2021 and is owned by Tenable, Inc. or an Affiliate thereof.
Modified 2021-07-08T00:00:00

Description

According to the version of the openssh packages installed, the EulerOS Virtualization installation on the remote host is affected by the following vulnerability :

  • DISPUTED The scp client in OpenSSH 8.2 incorrectly sends duplicate responses to the server upon a utimes system call failure, which allows a malicious unprivileged user on the remote server to overwrite arbitrary files in the client's download directory by creating a crafted subdirectory anywhere on the remote server. The victim must use the command scp -rp to download a file hierarchy containing, anywhere inside, this crafted subdirectory. NOTE: the vendor points out that 'this attack can achieve no more than a hostile peer is already able to achieve within the scp protocol' and 'utimes does not fail under normal circumstances.'(CVE-2020-12062)

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 Network Security, Inc.
#

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

if (description)
{
  script_id(151391);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/07/08");

  script_cve_id(
    "CVE-2020-12062"
  );

  script_name(english:"EulerOS Virtualization 3.0.2.2 : openssh (EulerOS-SA-2021-2153)");
  script_summary(english:"Checks the rpm output for the updated package.");

  script_set_attribute(attribute:"synopsis", value:
"The remote EulerOS Virtualization host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"According to the version of the openssh packages installed, the
EulerOS Virtualization installation on the remote host is affected by
the following vulnerability :

  - ** DISPUTED ** The scp client in OpenSSH 8.2
    incorrectly sends duplicate responses to the server
    upon a utimes system call failure, which allows a
    malicious unprivileged user on the remote server to
    overwrite arbitrary files in the client's download
    directory by creating a crafted subdirectory anywhere
    on the remote server. The victim must use the command
    scp -rp to download a file hierarchy containing,
    anywhere inside, this crafted subdirectory. NOTE: the
    vendor points out that 'this attack can achieve no more
    than a hostile peer is already able to achieve within
    the scp protocol' and 'utimes does not fail under
    normal circumstances.'(CVE-2020-12062)

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-2021-2153
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?1bbe92e0");
  script_set_attribute(attribute:"solution", value:
"Update the affected openssh package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"patch_publication_date", value:"2021/07/06");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/07/06");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:openssh");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:openssh-clients");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:openssh-server");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:pam_ssh_agent_auth");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:uvp:3.0.2.2");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2021 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/uvp_version");

  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/EulerOS/release");
if (isnull(release) || release !~ "^EulerOS") audit(AUDIT_OS_NOT, "EulerOS");
uvp = get_kb_item("Host/EulerOS/uvp_version");
if (uvp != "3.0.2.2") audit(AUDIT_OS_NOT, "EulerOS Virtualization 3.0.2.2");
if (!get_kb_item("Host/EulerOS/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$" && "aarch64" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "EulerOS", cpu);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_ARCH_NOT, "i686 / x86_64", cpu);

flag = 0;

pkgs = ["openssh-7.4p1-16.h20.eulerosv2r7",
        "openssh-clients-7.4p1-16.h20.eulerosv2r7",
        "openssh-server-7.4p1-16.h20.eulerosv2r7",
        "pam_ssh_agent_auth-0.10.3-2.16.h20.eulerosv2r7"];

foreach (pkg in pkgs)
  if (rpm_check(release:"EulerOS-2.0", reference:pkg)) 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, "openssh");
}