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nessusThis script is Copyright (C) 2023 and is owned by Tenable, Inc. or an Affiliate thereof.EULEROS_SA-2023-2523.NASL
HistoryJul 31, 2023 - 12:00 a.m.

EulerOS Virtualization 2.9.0 : curl (EulerOS-SA-2023-2523)

2023-07-3100:00:00
This script is Copyright (C) 2023 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
8
euleros
virtualization
curl
path traversal
authentication bypass
vulnerabilities
sftp
ftp
ssh
access control

According to the versions of the curl packages installed, the EulerOS Virtualization installation on the remote host is affected by the following vulnerabilities :

  • A path traversal vulnerability exists in curl <8.0.0 SFTP implementation causes the tilde (~) character to be wrongly replaced when used as a prefix in the first path element, in addition to its intended use as the first element to indicate a path relative to the user’s home directory. Attackers can exploit this flaw to bypass filtering or execute arbitrary code by crafting a path like /~2/foo while accessing a server with a specific user. (CVE-2023-27534)

  • An authentication bypass vulnerability exists in libcurl <8.0.0 in the FTP connection reuse feature that can result in wrong credentials being used during subsequent transfers. Previously created connections are kept in a connection pool for reuse if they match the current setup. However, certain FTP settings such as CURLOPT_FTP_ACCOUNT, CURLOPT_FTP_ALTERNATIVE_TO_USER, CURLOPT_FTP_SSL_CCC, and CURLOPT_USE_SSL were not included in the configuration match checks, causing them to match too easily. This could lead to libcurl using the wrong credentials when performing a transfer, potentially allowing unauthorized access to sensitive information. (CVE-2023-27535)

  • 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 authentication bypass vulnerability exists in libcurl prior to v8.0.0 where it reuses a previously established SSH connection despite the fact that an SSH option was modified, which should have prevented reuse. libcurl maintains a pool of previously used connections to reuse them for subsequent transfers if the configurations match. However, two SSH settings were omitted from the configuration check, allowing them to match easily, potentially leading to the reuse of an inappropriate connection. (CVE-2023-27538)

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.

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(179104);
  script_version("1.0");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/07/31");

  script_cve_id(
    "CVE-2023-27534",
    "CVE-2023-27535",
    "CVE-2023-27536",
    "CVE-2023-27538"
  );
  script_xref(name:"IAVA", value:"2023-A-0153-S");

  script_name(english:"EulerOS Virtualization 2.9.0 : curl (EulerOS-SA-2023-2523)");

  script_set_attribute(attribute:"synopsis", value:
"The remote EulerOS Virtualization host is missing multiple security updates.");
  script_set_attribute(attribute:"description", value:
"According to the versions of the curl packages installed, the EulerOS Virtualization installation on the remote host is
affected by the following vulnerabilities :

  - A path traversal vulnerability exists in curl <8.0.0 SFTP implementation causes the tilde (~) character to
    be wrongly replaced when used as a prefix in the first path element, in addition to its intended use as
    the first element to indicate a path relative to the user's home directory. Attackers can exploit this
    flaw to bypass filtering or execute arbitrary code by crafting a path like /~2/foo while accessing a
    server with a specific user. (CVE-2023-27534)

  - An authentication bypass vulnerability exists in libcurl <8.0.0 in the FTP connection reuse feature that
    can result in wrong credentials being used during subsequent transfers. Previously created connections are
    kept in a connection pool for reuse if they match the current setup. However, certain FTP settings such as
    CURLOPT_FTP_ACCOUNT, CURLOPT_FTP_ALTERNATIVE_TO_USER, CURLOPT_FTP_SSL_CCC, and CURLOPT_USE_SSL were not
    included in the configuration match checks, causing them to match too easily. This could lead to libcurl
    using the wrong credentials when performing a transfer, potentially allowing unauthorized access to
    sensitive information. (CVE-2023-27535)

  - 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 authentication bypass vulnerability exists in libcurl prior to v8.0.0 where it reuses a previously
    established SSH connection despite the fact that an SSH option was modified, which should have prevented
    reuse. libcurl maintains a pool of previously used connections to reuse them for subsequent transfers if
    the configurations match. However, two SSH settings were omitted from the configuration check, allowing
    them to match easily, potentially leading to the reuse of an inappropriate connection. (CVE-2023-27538)

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-2023-2523
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?860bafda");
  script_set_attribute(attribute:"solution", value:
"Update the affected curl packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2023-27534");

  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:"2023/03/20");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/08/01");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/07/31");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:curl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:libcurl");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:uvp:2.9.0");
  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:"Huawei 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/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 != "2.9.0") audit(AUDIT_OS_NOT, "EulerOS Virtualization 2.9.0");
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$" && "aarch64" >!< cpu && "x86" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "EulerOS", cpu);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "x86" >!< cpu) audit(AUDIT_ARCH_NOT, "i686 / x86_64", cpu);

var flag = 0;

var pkgs = [
  "curl-7.69.1-2.h21.eulerosv2r9",
  "libcurl-7.69.1-2.h21.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_HOLE,
    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");
}
VendorProductVersionCPE
huaweieuleroscurlp-cpe:/a:huawei:euleros:curl
huaweieuleroslibcurlp-cpe:/a:huawei:euleros:libcurl
huaweieulerosuvpcpe:/o:huawei:euleros:uvp:2.9.0