stunnel < 5.12 OpenSSL Multiple Vulnerabilities

#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(82077);
  script_version("1.14");
  script_cvs_date("Date: 2018/07/30 15:31:32");

  script_cve_id(
    "CVE-2015-0207",
    "CVE-2015-0208",
    "CVE-2015-0209",
    "CVE-2015-0285",
    "CVE-2015-0286",
    "CVE-2015-0287",
    "CVE-2015-0288",
    "CVE-2015-0289",
    "CVE-2015-0290",
    "CVE-2015-0291",
    "CVE-2015-0293",
    "CVE-2015-1787"
  );
  script_bugtraq_id(
    73225,
    73226,
    73227,
    73229,
    73230,
    73231,
    73232,
    73234,
    73235,
    73237,
    73238,
    73239
  );

  script_name(english:"stunnel < 5.12 OpenSSL Multiple Vulnerabilities");
  script_summary(english:"Checks the version of stunnel.exe.");

  script_set_attribute(attribute:"synopsis", value:
"The remote Windows host contains a program that is affected by
multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The version of stunnel installed on the remote host is prior to
version 5.12. It is, therefore, affected by the following
vulnerabilities in the bundled OpenSSL library :

  - A flaw exists in the DTLSv1_listen() function due to
    state information being preserved in the SSL object from
    one invocation to the next. A remote attacker can
    exploit this, via crafted DTLS traffic, to cause a
    segmentation fault, resulting in a denial of service.
    (CVE-2015-0207)

  - A flaw exists in the rsa_item_verify() function due to
    improper implementation of ASN.1 signature verification.
    A remote attacker can exploit this, via an ASN.1
    signature using the RSA PSS algorithm and invalid
    parameters, to cause a NULL pointer dereference,
    resulting in a denial of service. (CVE-2015-0208)

  - A use-after-free error exists in the d2i_ECPrivateKey()
    function due to improper processing of malformed EC
    private key files during import. A remote attacker can
    exploit this to dereference already freed memory,
    resulting in a denial of service or other unspecified
    impact. (CVE-2015-0209)

  - A flaw exists in the ssl3_client_hello() function due to
    improper validation of a PRNG seed before proceeding
    with a handshake, resulting in insufficient entropy and
    predictable output. A man-in-the-middle attacker can
    exploit this to defeat cryptographic protection
    mechanisms via a brute-force attack, resulting in the
    disclosure of sensitive information. (CVE-2015-0285)

  - An invalid read flaw exists in the ASN1_TYPE_cmp()
    function due to improperly performed boolean-type
    comparisons. A remote attacker can exploit this, via a
    crafted X.509 certificate to an endpoint that uses the
    certificate-verification feature, to cause an invalid
    read operation, resulting in a denial of service.
    (CVE-2015-0286)

  - A flaw exists in the ASN1_item_ex_d2i() function due to
    a failure to reinitialize 'CHOICE' and 'ADB' data
    structures when reusing a structure in ASN.1 parsing. A
    remote attacker can exploit this to cause an invalid
    write operation and memory corruption, resulting in a
    denial of service. (CVE-2015-0287)

  - A NULL pointer dereference flaw exists in the
    X509_to_X509_REQ() function due to improper processing
    of certificate keys. This allows a remote attacker, via
    a crafted X.509 certificate, to cause a denial of
    service. (CVE-2015-0288)

  - A NULL pointer dereference flaw exists in the PKCS#7
    parsing code due to incorrect handling of missing outer
    ContentInfo. This allows a remote attacker, using an
    application that processes arbitrary PKCS#7 data and
    providing malformed data with ASN.1 encoding, to cause
    a denial of service. (CVE-2015-0289)

  - A flaw exists with the 'multiblock' feature in the
    ssl3_write_bytes() function due to improper handling of
    certain non-blocking I/O cases. This allows a remote
    attacker to cause failed connections or a segmentation
    fault, resulting in a denial of service. (CVE-2015-0290)

  - A NULL pointer dereference flaw exists when handling
    clients attempting to renegotiate using an invalid
    signature algorithm extension. A remote attacker can
    exploit this to cause a denial of service.
    (CVE-2015-0291)

  - A flaw exists in servers that both support SSLv2 and
    enable export cipher suites due to improper
    implementation of SSLv2. A remote attacker can exploit
    this, via a crafted CLIENT-MASTER-KEY message, to cause
    a denial of service. (CVE-2015-0293)

  - A flaw exists in the ssl3_get_client_key_exchange()
    function when client authentication and an ephemeral
    Diffie-Hellman ciphersuite are enabled. A remote
    attacker can exploit this, via a ClientKeyExchange
    message with a length of zero, to cause a denial of
    service. (CVE-2015-1787)

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://www.openssl.org/news/secadv/20150319.txt");
  # https://www.stunnel.org/pipermail/stunnel-announce/2015-March/000094.html
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?cdf29d06");
  script_set_attribute(attribute:"solution", value:
"Upgrade to Stunnel 5.12 or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2015/03/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2015/03/19");
  script_set_attribute(attribute:"plugin_publication_date", value:"2015/03/25");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:stunnel:stunnel");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Windows");

  script_copyright(english:"This script is Copyright (C) 2015-2018 Tenable Network Security, Inc.");

  script_dependencies("stunnel_installed.nasl");
  script_require_keys("installed_sw/stunnel");

  exit(0);
}

include("audit.inc");
include("global_settings.inc");
include("misc_func.inc");
include("install_func.inc");

app = 'stunnel';
install = get_single_install(app_name:app, exit_if_unknown_ver:TRUE);

version = install["version"];
path = install["path"];

# Affected < 5.12
if (
  version =~ "^[0-4]\." ||
  version =~ "^5\.(0[0-9]|10|11)($|[^0-9])"
)
{
  port = get_kb_item("SMB/transport");
  if (!port) port = 445;

  report =
    '\n  Path              : ' + path +
    '\n  Installed version : ' + version +
    '\n  Fixed version     : 5.12' +
    '\n';
  security_report_v4(severity:SECURITY_WARNING, port:port, extra:report);
}
else audit(AUDIT_INST_PATH_NOT_VULN, app, version, path);