Lucene search

K
nessusThis script is Copyright (C) 2022-2023 and is owned by Tenable, Inc. or an Affiliate thereof.ALMA_LINUX_ALSA-2021-4059.NASL
HistoryFeb 09, 2022 - 12:00 a.m.

AlmaLinux 8 : curl (ALSA-2021:4059)

2022-02-0900:00:00
This script is Copyright (C) 2022-2023 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
39
almalinux 8
vulnerabilities
curl
tls
imap
pop3
ftp
security advisory
cve-2021-22946
cve-2021-22947
nessus scanner

CVSS2

5

Attack Vector

NETWORK

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

NONE

Availability Impact

NONE

AV:N/AC:L/Au:N/C:P/I:N/A:N

CVSS3

7.5

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

NONE

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

AI Score

8.4

Confidence

High

EPSS

0.003

Percentile

69.8%

The remote AlmaLinux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the ALSA-2021:4059 advisory.

  • A user can tell curl >= 7.20.0 and <= 7.78.0 to require a successful upgrade to TLS when speaking to an IMAP, POP3 or FTP server (--ssl-reqd on the command line orCURLOPT_USE_SSL set to CURLUSESSL_CONTROL or CURLUSESSL_ALL withlibcurl). This requirement could be bypassed if the server would return a properly crafted but perfectly legitimate response.This flaw would then make curl silently continue its operations
    withoutTLS contrary to the instructions and expectations, exposing possibly sensitive data in clear text over the network. (CVE-2021-22946)

  • When curl >= 7.20.0 and <= 7.78.0 connects to an IMAP or POP3 server to retrieve data using STARTTLS to upgrade to TLS security, the server can respond and send back multiple responses at once that curl caches.
    curl would then upgrade to TLS but not flush the in-queue of cached responses but instead continue using and trustingthe responses it got before the TLS handshake as if they were authenticated.Using this flaw, it allows a Man-In-The-Middle attacker to first inject the fake responses, then pass-through the TLS traffic from the legitimate server and trick curl into sending data back to the user thinking the attacker’s injected data comes from the TLS-protected server. (CVE-2021-22947)

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-2021:4059.
##

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

if (description)
{
  script_id(157603);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/11/10");

  script_cve_id("CVE-2021-22946", "CVE-2021-22947");
  script_xref(name:"ALSA", value:"2021:4059");
  script_xref(name:"IAVA", value:"2022-A-0030-S");

  script_name(english:"AlmaLinux 8 : curl (ALSA-2021:4059)");

  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-2021:4059 advisory.

  - A user can tell curl >= 7.20.0 and <= 7.78.0 to require a successful upgrade to TLS when speaking to an
    IMAP, POP3 or FTP server (`--ssl-reqd` on the command line or`CURLOPT_USE_SSL` set to `CURLUSESSL_CONTROL`
    or `CURLUSESSL_ALL` withlibcurl). This requirement could be bypassed if the server would return a properly
    crafted but perfectly legitimate response.This flaw would then make curl silently continue its operations
    **withoutTLS** contrary to the instructions and expectations, exposing possibly sensitive data in clear
    text over the network. (CVE-2021-22946)

  - When curl >= 7.20.0 and <= 7.78.0 connects to an IMAP or POP3 server to retrieve data using STARTTLS to
    upgrade to TLS security, the server can respond and send back multiple responses at once that curl caches.
    curl would then upgrade to TLS but not flush the in-queue of cached responses but instead continue using
    and trustingthe responses it got *before* the TLS handshake as if they were authenticated.Using this flaw,
    it allows a Man-In-The-Middle attacker to first inject the fake responses, then pass-through the TLS
    traffic from the legitimate server and trick curl into sending data back to the user thinking the
    attacker's injected data comes from the TLS-protected server. (CVE-2021-22947)

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-2021-4059.html");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N");
  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:H/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:F/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-22946");

  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:"2021/09/17");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/11/02");
  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: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:"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) 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':'curl-7.61.1-18.el8_4.2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libcurl-7.61.1-18.el8_4.2', 'cpu':'i686', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libcurl-7.61.1-18.el8_4.2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libcurl-devel-7.61.1-18.el8_4.2', 'cpu':'i686', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libcurl-devel-7.61.1-18.el8_4.2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libcurl-minimal-7.61.1-18.el8_4.2', 'cpu':'i686', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libcurl-minimal-7.61.1-18.el8_4.2', '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, 'curl / libcurl / libcurl-devel / libcurl-minimal');
}

CVSS2

5

Attack Vector

NETWORK

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

NONE

Availability Impact

NONE

AV:N/AC:L/Au:N/C:P/I:N/A:N

CVSS3

7.5

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

NONE

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

AI Score

8.4

Confidence

High

EPSS

0.003

Percentile

69.8%