Squid 3.1.x < 3.3.12 / 3.4.4 HTTPS Request Handling DoS

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

include("compat.inc");

if (description)
{
  script_id(73131);
  script_version("1.5");
  script_cvs_date("Date: 2019/11/26");

  script_cve_id("CVE-2014-0128");
  script_bugtraq_id(66112);

  script_name(english:"Squid 3.1.x < 3.3.12 / 3.4.4 HTTPS Request Handling DoS");
  script_summary(english:"Checks version of Squid");

  script_set_attribute(attribute:"synopsis", value:
"The remote proxy server is affected by a denial of service
vulnerability.");
  script_set_attribute(attribute:"description", value:
"According to its banner, the version of Squid running on the remote
host is 3.x prior to 3.3.12 or 3.4.4 and is, therefore, affected by a
denial of service vulnerability. 

A flaw exists in SSL-Bump in regards to the state management when
processing range requests.  A remote attacker can cause the server to
crash with specially crafted HTTPS requests. 

Note that Nessus has relied only on the version in the proxy server's
banner, which is not updated by the patch the project has released to
address the issue.  If this patch has been applied properly and the
service has been restarted, consider this to be a false positive.");
  script_set_attribute(attribute:"see_also", value:"http://www.squid-cache.org/Advisories/SQUID-2014_1.txt");
  # http://www.squid-cache.org/Versions/v3/3.3/changesets/squid-3.3-12677.patch
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?bf7922a2");
  # http://www.squid-cache.org/Versions/v3/3.4/changesets/squid-3.4-13104.patch
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?13763a56");
  script_set_attribute(attribute:"solution", value:
"Either upgrade to Squid version 3.3.12 / 3.4.4 or later, or apply the
vendor-supplied patch.");
  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:U/RL:OF/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2014-0128");

  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:"2014/03/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2014/03/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2014/03/21");

  script_set_attribute(attribute:"potential_vulnerability", value:"true");
  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:squid-cache:squid");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2014-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("squid_version.nasl");
  script_require_keys("www/squid", "Settings/ParanoidReport");
  script_require_ports("Services/http_proxy", 3128, 8080);

  exit(0);
}

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

# Build a list of ports from the
list = get_kb_list("http_proxy/*/squid/version");
if (isnull(list)) audit(AUDIT_NOT_INST, "Squid");

# nb: banner checks of open source software are prone to false-
#     positives so only run the check if reporting is paranoid.
if (report_paranoia < 2) audit(AUDIT_PARANOID);

vulnerable = FALSE;
not_vuln_list = make_list();

foreach item (keys(list))
{
  port = ereg_replace(pattern:'^http_proxy/([0-9]+)/squid/version', replace:'\\1', string:item);
  version = list[item];

  # Affected:
  # Squid 3.1.x < 3.3.12
  # Squid 3.4.x < 3.4.4
  if (
    version =~ "^3\.[12]([^0-9]|$)" ||
    version =~ "^3\.3\.([0-9]|1[0-1])([^0-9]|$)" ||
    version =~ "^3\.4\.[0-3]([^0-9]|$)"
  )
  {
    vulnerable = TRUE;
    if (report_verbosity > 0)
    {
      source = get_kb_item('http_proxy/'+port+'/squid/source');
      report =
        '\n  Version source    : ' + source +
        '\n  Installed version : ' + version +
        '\n  Fixed version     : 3.3.12 / 3.4.4' + '\n';
      security_warning(port:port, extra:report);
    }
    else security_warning(port);
  }
  else not_vuln_list = make_list(not_vuln_list, version + " on port " + port);
}

if (vulnerable) exit(0);
else
{
  installs = max_index(not_vuln_list);
  if (installs == 0) audit(AUDIT_NOT_INST, "Squid");
  else if (installs == 1)
    audit(AUDIT_INST_VER_NOT_VULN, "Squid", not_vuln_list[0]);
  else
    exit(0, "The Squid installs ("+ join(not_vuln_list, sep:", ") + ") are not affected.");
}