CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AI Score
Confidence
High
EPSS
Percentile
76.9%
The remote AlmaLinux 8 host has packages installed that are affected by a vulnerability as referenced in the ALSA-2021:1593 advisory.
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 70300
##
# (C) Tenable Network Security, Inc.
#
# The package checks in this plugin were extracted from
# AlmaLinux Security Advisory ALSA-2021:1593.
##
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(157701);
script_version("1.5");
script_set_attribute(attribute:"plugin_modification_date", value:"2023/11/10");
script_cve_id("CVE-2020-28196");
script_xref(name:"ALSA", value:"2021:1593");
script_xref(name:"CEA-ID", value:"CEA-2021-0025");
script_name(english:"AlmaLinux 8 : krb5 (ALSA-2021:1593)");
script_set_attribute(attribute:"synopsis", value:
"The remote AlmaLinux host is missing a security update.");
script_set_attribute(attribute:"description", value:
"The remote AlmaLinux 8 host has packages installed that are affected by a vulnerability as referenced in the
ALSA-2021:1593 advisory.
- MIT Kerberos 5 (aka krb5) before 1.17.2 and 1.18.x before 1.18.3 allows unbounded recursion via an
ASN.1-encoded Kerberos message because the lib/krb5/asn.1/asn1_encode.c support for BER indefinite lengths
lacks a recursion limit. (CVE-2020-28196)
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://errata.almalinux.org/8/ALSA-2021-1593.html");
script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
script_set_cvss_temporal_vector("CVSS2#E:F/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:N/A:H");
script_set_cvss3_temporal_vector("CVSS:3.0/E:F/RL:O/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-28196");
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:"2020/11/05");
script_set_attribute(attribute:"patch_publication_date", value:"2021/05/18");
script_set_attribute(attribute:"plugin_publication_date", value:"2022/02/09");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:krb5-devel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:krb5-libs");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:krb5-pkinit");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:krb5-server");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:krb5-server-ldap");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:krb5-workstation");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:libkadm5");
script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Alma Linux 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/AlmaLinux/release", "Host/AlmaLinux/rpm-list", "Host/cpu");
exit(0);
}
include('audit.inc');
include('global_settings.inc');
include('misc_func.inc');
include('rpm.inc');
if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var release = get_kb_item('Host/AlmaLinux/release');
if (isnull(release) || 'AlmaLinux' >!< release) audit(AUDIT_OS_NOT, 'AlmaLinux');
var os_ver = pregmatch(pattern: "AlmaLinux release ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'AlmaLinux');
var os_ver = os_ver[1];
if (! preg(pattern:"^8([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'AlmaLinux 8.x', 'AlmaLinux ' + os_ver);
if (!get_kb_item('Host/AlmaLinux/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);
var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'AlmaLinux', cpu);
var pkgs = [
{'reference':'krb5-devel-1.18.2-8.el8', 'cpu':'i686', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
{'reference':'krb5-devel-1.18.2-8.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
{'reference':'krb5-libs-1.18.2-8.el8', 'cpu':'i686', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
{'reference':'krb5-libs-1.18.2-8.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
{'reference':'krb5-pkinit-1.18.2-8.el8', 'cpu':'i686', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
{'reference':'krb5-pkinit-1.18.2-8.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
{'reference':'krb5-server-1.18.2-8.el8', 'cpu':'i686', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
{'reference':'krb5-server-1.18.2-8.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
{'reference':'krb5-server-ldap-1.18.2-8.el8', 'cpu':'i686', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
{'reference':'krb5-server-ldap-1.18.2-8.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
{'reference':'krb5-workstation-1.18.2-8.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
{'reference':'libkadm5-1.18.2-8.el8', 'cpu':'i686', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
{'reference':'libkadm5-1.18.2-8.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE}
];
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 = 'Alma-' + 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 && (!exists_check || rpm_exists(release:release, rpm:exists_check))) {
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, 'krb5-devel / krb5-libs / krb5-pkinit / krb5-server / krb5-server-ldap / etc');
}
Vendor | Product | Version | CPE |
---|---|---|---|
alma | linux | krb5-devel | p-cpe:/a:alma:linux:krb5-devel |
alma | linux | krb5-libs | p-cpe:/a:alma:linux:krb5-libs |
alma | linux | krb5-pkinit | p-cpe:/a:alma:linux:krb5-pkinit |
alma | linux | krb5-server | p-cpe:/a:alma:linux:krb5-server |
alma | linux | krb5-server-ldap | p-cpe:/a:alma:linux:krb5-server-ldap |
alma | linux | krb5-workstation | p-cpe:/a:alma:linux:krb5-workstation |
alma | linux | libkadm5 | p-cpe:/a:alma:linux:libkadm5 |
alma | linux | 8 | cpe:/o:alma:linux:8 |
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AI Score
Confidence
High
EPSS
Percentile
76.9%