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
EPSS
Percentile
71.9%
The remote AlmaLinux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the ALSA-2023:4523 advisory.
An authentication bypass vulnerability exists libcurl <8.0.0 in the connection reuse feature which can reuse previously established connections with incorrect user permissions due to a failure to check for changes in the CURLOPT_GSSAPI_DELEGATION option. This vulnerability affects krb5/kerberos/negotiate/GSSAPI transfers and could potentially result in unauthorized access to sensitive information. The safest option is to not reuse connections if the CURLOPT_GSSAPI_DELEGATION option has been changed. (CVE-2023-27536)
An improper certificate validation vulnerability exists in curl <v8.1.0 in the way it supports matching of wildcard patterns when listed as Subject Alternative Name in TLS server certificates. curl can be built to use its own name matching function for TLS rather than one provided by a TLS library. This private wildcard matching function would match IDN (International Domain Name) hosts incorrectly and could as a result accept patterns that otherwise should mismatch. IDN hostnames are converted to puny code before used for certificate checks. Puny coded names always start with xn--
and should not be allowed to pattern match, but the wildcard check in curl could still check for x*
, which would match even though the IDN name most likely contained nothing even resembling an x
. (CVE-2023-28321)
Note that Nessus has not tested for these issues but has instead relied only on the application’s self-reported version number.
#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The package checks in this plugin were extracted from
# AlmaLinux Security Advisory ALSA-2023:4523.
##
include('compat.inc');
if (description)
{
script_id(179622);
script_version("1.0");
script_set_attribute(attribute:"plugin_modification_date", value:"2023/08/09");
script_cve_id("CVE-2023-27536", "CVE-2023-28321");
script_xref(name:"ALSA", value:"2023:4523");
script_xref(name:"IAVA", value:"2023-A-0153-S");
script_xref(name:"IAVA", value:"2023-A-0259-S");
script_name(english:"AlmaLinux 8 : curl (ALSA-2023:4523)");
script_set_attribute(attribute:"synopsis", value:
"The remote AlmaLinux host is missing one or more security updates.");
script_set_attribute(attribute:"description", value:
"The remote AlmaLinux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the
ALSA-2023:4523 advisory.
- An authentication bypass vulnerability exists libcurl <8.0.0 in the connection reuse feature which can
reuse previously established connections with incorrect user permissions due to a failure to check for
changes in the CURLOPT_GSSAPI_DELEGATION option. This vulnerability affects krb5/kerberos/negotiate/GSSAPI
transfers and could potentially result in unauthorized access to sensitive information. The safest option
is to not reuse connections if the CURLOPT_GSSAPI_DELEGATION option has been changed. (CVE-2023-27536)
- An improper certificate validation vulnerability exists in curl <v8.1.0 in the way it supports matching of
wildcard patterns when listed as Subject Alternative Name in TLS server certificates. curl can be built
to use its own name matching function for TLS rather than one provided by a TLS library. This private
wildcard matching function would match IDN (International Domain Name) hosts incorrectly and could as a
result accept patterns that otherwise should mismatch. IDN hostnames are converted to puny code before
used for certificate checks. Puny coded names always start with `xn--` and should not be allowed to
pattern match, but the wildcard check in curl could still check for `x*`, which would match even though
the IDN name most likely contained nothing even resembling an `x`. (CVE-2023-28321)
Note that Nessus has not tested for these issues 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-2023-4523.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-2023-28321");
script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
script_set_attribute(attribute:"exploit_available", value:"true");
script_cwe_id(295, 305);
script_set_attribute(attribute:"vuln_publication_date", value:"2023/03/20");
script_set_attribute(attribute:"patch_publication_date", value:"2023/08/08");
script_set_attribute(attribute:"plugin_publication_date", value:"2023/08/09");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:curl");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:libcurl");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:libcurl-devel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:libcurl-minimal");
script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8");
script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::appstream");
script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::baseos");
script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::highavailability");
script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::nfv");
script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::powertools");
script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::realtime");
script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::resilientstorage");
script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::sap");
script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::sap_hana");
script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::supplementary");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_set_attribute(attribute:"stig_severity", value:"I");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Alma Linux Local Security Checks");
script_copyright(english:"This script is Copyright (C) 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('rpm.inc');
if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/AlmaLinux/release');
if (isnull(os_release) || 'AlmaLinux' >!< os_release) audit(AUDIT_OS_NOT, 'AlmaLinux');
var os_ver = pregmatch(pattern: "AlmaLinux release ([0-9]+(\.[0-9]+)?)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'AlmaLinux');
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':'curl-7.61.1-30.el8_8.3', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
{'reference':'libcurl-7.61.1-30.el8_8.3', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
{'reference':'libcurl-devel-7.61.1-30.el8_8.3', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
{'reference':'libcurl-minimal-7.61.1-30.el8_8.3', '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, 'curl / libcurl / libcurl-devel / libcurl-minimal');
}