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nessusThis script is Copyright (C) 2024 and is owned by Tenable, Inc. or an Affiliate thereof.ORACLELINUX_ELSA-2024-12233.NASL
HistoryMar 19, 2024 - 12:00 a.m.

Oracle Linux 7 : openssh (ELSA-2024-12233)

2024-03-1900:00:00
This script is Copyright (C) 2024 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
8
oracle linux 7
openssh vulnerability
elsa-2024-12233
terrapin attack
ssh transport protocol
integrity checks
sequence numbers
cve-2023-48795

5.9 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

HIGH

Availability Impact

NONE

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

7.4 High

AI Score

Confidence

Low

0.962 High

EPSS

Percentile

99.5%

The remote Oracle Linux 7 host has packages installed that are affected by a vulnerability as referenced in the ELSA-2024-12233 advisory.

  • The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the extension negotiation message), and a client and server may consequently end up with a connection for which some security features have been downgraded or disabled, aka a Terrapin attack. This occurs because the SSH Binary Packet Protocol (BPP), implemented by these extensions, mishandles the handshake phase and mishandles use of sequence numbers. For example, there is an effective attack against SSH’s use of ChaCha20-Poly1305 (and CBC with Encrypt-then-MAC). The bypass occurs in [email protected] and (if CBC is used) the [email protected] MAC algorithms. This also affects Maverick Synergy Java SSH API before 3.1.0-SNAPSHOT, Dropbear through 2022.83, Ssh before 5.1.1 in Erlang/OTP, PuTTY before 0.80, AsyncSSH before 2.14.2, golang.org/x/crypto before 0.17.0, libssh before 0.10.6, libssh2 through 1.11.0, Thorn Tech SFTP Gateway before 3.4.6, Tera Term before 5.1, Paramiko before 3.4.0, jsch before 0.2.15, SFTPGo before 2.5.6, Netgate pfSense Plus through 23.09.1, Netgate pfSense CE through 2.7.2, HPN-SSH through 18.2.0, ProFTPD before 1.3.8b (and before 1.3.9rc2), ORYX CycloneSSH before 2.3.4, NetSarang XShell 7 before Build 0144, CrushFTP before 10.6.0, ConnectBot SSH library before 2.2.22, Apache MINA sshd through 2.11.0, sshj through 0.37.0, TinySSH through 20230101, trilead-ssh2 6401, LANCOM LCOS and LANconfig, FileZilla before 3.66.4, Nova before 11.8, PKIX-SSH before 14.4, SecureCRT before 9.4.3, Transmit5 before 5.10.4, Win32-OpenSSH before 9.5.0.0p1-Beta, WinSCP before 6.2.2, Bitvise SSH Server before 9.32, Bitvise SSH Client before 9.33, KiTTY through 0.76.1.13, the net-ssh gem 7.2.0 for Ruby, the mscdex ssh2 module before 1.15.0 for Node.js, the thrussh library before 0.35.1 for Rust, and the Russh crate before 0.40.2 for Rust. (CVE-2023-48795)

Note that Nessus has not tested for this issue but has instead relied only on the application’s self-reported version number.

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Oracle Linux Security Advisory ELSA-2024-12233.
##

include('compat.inc');

if (description)
{
  script_id(192241);
  script_version("1.0");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/03/19");

  script_cve_id("CVE-2023-48795");

  script_name(english:"Oracle Linux 7 : openssh (ELSA-2024-12233)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Oracle Linux host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The remote Oracle Linux 7 host has packages installed that are affected by a vulnerability as referenced in the
ELSA-2024-12233 advisory.

  - The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other
    products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the
    extension negotiation message), and a client and server may consequently end up with a connection for
    which some security features have been downgraded or disabled, aka a Terrapin attack. This occurs because
    the SSH Binary Packet Protocol (BPP), implemented by these extensions, mishandles the handshake phase and
    mishandles use of sequence numbers. For example, there is an effective attack against SSH's use of
    ChaCha20-Poly1305 (and CBC with Encrypt-then-MAC). The bypass occurs in [email protected] and
    (if CBC is used) the [email protected] MAC algorithms. This also affects Maverick Synergy Java SSH API
    before 3.1.0-SNAPSHOT, Dropbear through 2022.83, Ssh before 5.1.1 in Erlang/OTP, PuTTY before 0.80,
    AsyncSSH before 2.14.2, golang.org/x/crypto before 0.17.0, libssh before 0.10.6, libssh2 through 1.11.0,
    Thorn Tech SFTP Gateway before 3.4.6, Tera Term before 5.1, Paramiko before 3.4.0, jsch before 0.2.15,
    SFTPGo before 2.5.6, Netgate pfSense Plus through 23.09.1, Netgate pfSense CE through 2.7.2, HPN-SSH
    through 18.2.0, ProFTPD before 1.3.8b (and before 1.3.9rc2), ORYX CycloneSSH before 2.3.4, NetSarang
    XShell 7 before Build 0144, CrushFTP before 10.6.0, ConnectBot SSH library before 2.2.22, Apache MINA sshd
    through 2.11.0, sshj through 0.37.0, TinySSH through 20230101, trilead-ssh2 6401, LANCOM LCOS and
    LANconfig, FileZilla before 3.66.4, Nova before 11.8, PKIX-SSH before 14.4, SecureCRT before 9.4.3,
    Transmit5 before 5.10.4, Win32-OpenSSH before 9.5.0.0p1-Beta, WinSCP before 6.2.2, Bitvise SSH Server
    before 9.32, Bitvise SSH Client before 9.33, KiTTY through 0.76.1.13, the net-ssh gem 7.2.0 for Ruby, the
    mscdex ssh2 module before 1.15.0 for Node.js, the thrussh library before 0.35.1 for Rust, and the Russh
    crate before 0.40.2 for Rust. (CVE-2023-48795)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://linux.oracle.com/errata/ELSA-2024-12233.html");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:N/I:C/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2023-48795");

  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:"2023/12/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2024/03/18");
  script_set_attribute(attribute:"plugin_publication_date", value:"2024/03/19");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:oracle:linux:7::u8_security_validation");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:linux:7");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:openssh");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:openssh-askpass");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:openssh-cavs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:openssh-clients");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:openssh-keycat");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:openssh-ldap");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:openssh-server");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:openssh-server-sysvinit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:pam_ssh_agent_auth");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

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

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

  exit(0);
}


include('rpm.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item('Host/OracleLinux')) audit(AUDIT_OS_NOT, 'Oracle Linux');
var os_release = get_kb_item("Host/RedHat/release");
if (isnull(os_release) || !pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux)", string:os_release)) audit(AUDIT_OS_NOT, 'Oracle Linux');
var os_ver = pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux) .*release ([0-9]+(\.[0-9]+)?)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Oracle Linux');
os_ver = os_ver[1];
if (! preg(pattern:"^7([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Oracle Linux 7', 'Oracle Linux ' + os_ver);

if (!get_kb_item('Host/RedHat/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, 'Oracle Linux', cpu);
if ('aarch64' >!< cpu) audit(AUDIT_ARCH_NOT, 'aarch64', cpu);

var pkgs = [
    {'reference':'openssh-7.4p1-23.0.3.el7_9_fips', 'cpu':'aarch64', 'release':'7', 'el_string':'el7_9_fips', 'rpm_spec_vers_cmp':TRUE, 'epoch':'10', 'allowmaj':TRUE},
    {'reference':'openssh-askpass-7.4p1-23.0.3.el7_9_fips', 'cpu':'aarch64', 'release':'7', 'el_string':'el7_9_fips', 'rpm_spec_vers_cmp':TRUE, 'epoch':'10', 'allowmaj':TRUE},
    {'reference':'openssh-cavs-7.4p1-23.0.3.el7_9_fips', 'cpu':'aarch64', 'release':'7', 'el_string':'el7_9_fips', 'rpm_spec_vers_cmp':TRUE, 'epoch':'10', 'allowmaj':TRUE},
    {'reference':'openssh-clients-7.4p1-23.0.3.el7_9_fips', 'cpu':'aarch64', 'release':'7', 'el_string':'el7_9_fips', 'rpm_spec_vers_cmp':TRUE, 'epoch':'10', 'allowmaj':TRUE},
    {'reference':'openssh-keycat-7.4p1-23.0.3.el7_9_fips', 'cpu':'aarch64', 'release':'7', 'el_string':'el7_9_fips', 'rpm_spec_vers_cmp':TRUE, 'epoch':'10', 'allowmaj':TRUE},
    {'reference':'openssh-ldap-7.4p1-23.0.3.el7_9_fips', 'cpu':'aarch64', 'release':'7', 'el_string':'el7_9_fips', 'rpm_spec_vers_cmp':TRUE, 'epoch':'10', 'allowmaj':TRUE},
    {'reference':'openssh-server-7.4p1-23.0.3.el7_9_fips', 'cpu':'aarch64', 'release':'7', 'el_string':'el7_9_fips', 'rpm_spec_vers_cmp':TRUE, 'epoch':'10', 'allowmaj':TRUE},
    {'reference':'openssh-server-sysvinit-7.4p1-23.0.3.el7_9_fips', 'cpu':'aarch64', 'release':'7', 'el_string':'el7_9_fips', 'rpm_spec_vers_cmp':TRUE, 'epoch':'10', 'allowmaj':TRUE},
    {'reference':'pam_ssh_agent_auth-0.10.3-2.23.0.3.el7_9_fips', 'cpu':'aarch64', 'release':'7', 'el_string':'el7_9_fips', 'rpm_spec_vers_cmp':TRUE, 'epoch':'10'}
];

var flag = 0;
foreach var package_array ( pkgs ) {
  var reference = NULL;
  var _release = NULL;
  var sp = NULL;
  var _cpu = NULL;
  var el_string = NULL;
  var rpm_spec_vers_cmp = NULL;
  var epoch = NULL;
  var allowmaj = NULL;
  var exists_check = NULL;
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (!empty_or_null(package_array['release'])) _release = 'EL' + package_array['release'];
  if (!empty_or_null(package_array['sp'])) sp = package_array['sp'];
  if (!empty_or_null(package_array['cpu'])) _cpu = package_array['cpu'];
  if (!empty_or_null(package_array['el_string'])) el_string = package_array['el_string'];
  if (!empty_or_null(package_array['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = package_array['rpm_spec_vers_cmp'];
  if (!empty_or_null(package_array['epoch'])) epoch = package_array['epoch'];
  if (!empty_or_null(package_array['allowmaj'])) allowmaj = package_array['allowmaj'];
  if (!empty_or_null(package_array['exists_check'])) exists_check = package_array['exists_check'];
  if (reference && _release) {
    if (exists_check) {
        if (rpm_exists(release:_release, rpm:exists_check) && rpm_check(release:_release, sp:sp, cpu:cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj)) flag++;
    } else {
        if (rpm_check(release:_release, sp:sp, cpu:_cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj)) 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, 'openssh / openssh-askpass / openssh-cavs / etc');
}
VendorProductVersionCPE
oraclelinux7cpe:/a:oracle:linux:7::u8_security_validation
oraclelinux7cpe:/o:oracle:linux:7
oraclelinuxopensshp-cpe:/a:oracle:linux:openssh
oraclelinuxopenssh-askpassp-cpe:/a:oracle:linux:openssh-askpass
oraclelinuxopenssh-cavsp-cpe:/a:oracle:linux:openssh-cavs
oraclelinuxopenssh-clientsp-cpe:/a:oracle:linux:openssh-clients
oraclelinuxopenssh-keycatp-cpe:/a:oracle:linux:openssh-keycat
oraclelinuxopenssh-ldapp-cpe:/a:oracle:linux:openssh-ldap
oraclelinuxopenssh-serverp-cpe:/a:oracle:linux:openssh-server
oraclelinuxopenssh-server-sysvinitp-cpe:/a:oracle:linux:openssh-server-sysvinit
Rows per page:
1-10 of 111

5.9 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

HIGH

Availability Impact

NONE

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

7.4 High

AI Score

Confidence

Low

0.962 High

EPSS

Percentile

99.5%