EulerOS Virtualization 2.9.1 : libssh (EulerOS-SA-2021-2753)

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

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

if (description)
{
  script_id(155484);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/06");

  script_cve_id("CVE-2021-3634");
  script_xref(name:"IAVA", value:"2022-A-0041-S");

  script_name(english:"EulerOS Virtualization 2.9.1 : libssh (EulerOS-SA-2021-2753)");

  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 versions of the libssh package installed, the EulerOS Virtualization installation on the remote host is
affected by the following vulnerabilities :

  - A flaw has been found in libssh in versions prior to 0.9.6. The SSH protocol keeps track of two shared
    secrets during the lifetime of the session. One of them is called secret_hash and the other session_id.
    Initially, both of them are the same, but after key re-exchange, previous session_id is kept and used as
    an input to new secret_hash. Historically, both of these buffers had shared length variable, which worked
    as long as these buffers were same. But the key re-exchange operation can also change the key exchange
    method, which can be based on hash of different size, eventually creating 'secret_hash' of different size
    than the session_id has. This becomes an issue when the session_id memory is zeroed or when it is used
    again during second key re-exchange. (CVE-2021-3634)

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-2021-2753
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?da3e907b");
  script_set_attribute(attribute:"solution", value:
"Update the affected libssh packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:N/I:N/A:P");
  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:L/UI:N/S:U/C:N/I:N/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-2021-3634");

  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:"2021/08/31");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/11/17");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/11/17");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:libssh");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:uvp:2.9.1");
  script_set_attribute(attribute:"stig_severity", value:"II");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2021-2023 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/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 (uvp != "2.9.1") audit(AUDIT_OS_NOT, "EulerOS Virtualization 2.9.1");
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 = [
  "libssh-0.9.4-1.h3.eulerosv2r9"
];

foreach (var 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
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "libssh");
}