CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:M/Au:N/C:C/I:C/A:C
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
Percentile
91.5%
The Cisco WebEx Extension for Chrome installed on the remote host is a version prior to 1.0.12. It is, therefore, affected by a remote code execution vulnerability in the ‘atgpcext’ library due to incomplete GPC sanitization. An unauthenticated, remote attacker can exploit this, by convincing a user to visit a specially crafted website, to execute arbitrary code with the privileges of the affected browser.
#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(101816);
script_version("1.5");
script_set_attribute(attribute:"plugin_modification_date", value:"2022/04/11");
script_cve_id("CVE-2017-6753");
script_bugtraq_id(99614);
script_xref(name:"CISCO-SA", value:"cisco-sa-20170717-webex");
script_xref(name:"CISCO-BUG-ID", value:"CSCvf15012");
script_xref(name:"CISCO-BUG-ID", value:"CSCvf15020");
script_xref(name:"CISCO-BUG-ID", value:"CSCvf15030");
script_xref(name:"CISCO-BUG-ID", value:"CSCvf15033");
script_xref(name:"CISCO-BUG-ID", value:"CSCvf15036");
script_xref(name:"CISCO-BUG-ID", value:"CSCvf15037");
script_xref(name:"IAVA", value:"2017-A-0216");
script_name(english:"Cisco WebEx Extension for Chrome < 1.0.12 'atgpcext' Library GPC Sanitization RCE (cisco-sa-20170717-webex)");
script_set_attribute(attribute:"synopsis", value:
"A browser extension installed on the remote host is affected by a
remote code execution vulnerability.");
script_set_attribute(attribute:"description", value:
"The Cisco WebEx Extension for Chrome installed on the remote host is a
version prior to 1.0.12. It is, therefore, affected by a remote code
execution vulnerability in the 'atgpcext' library due to incomplete
GPC sanitization. An unauthenticated, remote attacker can exploit
this, by convincing a user to visit a specially crafted website, to
execute arbitrary code with the privileges of the affected browser.");
# https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170717-webex
script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?0a976aaa");
script_set_attribute(attribute:"see_also", value:"https://bugs.chromium.org/p/project-zero/issues/detail?id=1324");
script_set_attribute(attribute:"see_also", value:"https://thehackernews.com/2017/07/cisco-webex-vulnerability.html");
script_set_attribute(attribute:"solution", value:
"Upgrade to Cisco WebEx Extension for Chrome version 1.0.12 or later.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:C");
script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H");
script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
script_set_attribute(attribute:"exploit_available", value:"false");
script_set_attribute(attribute:"in_the_news", value:"true");
script_set_attribute(attribute:"vuln_publication_date", value:"2017/07/17");
script_set_attribute(attribute:"patch_publication_date", value:"2017/07/17");
script_set_attribute(attribute:"plugin_publication_date", value:"2017/07/19");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"cpe:/a:google:chrome");
script_set_attribute(attribute:"cpe", value:"cpe:/a:cisco:webex");
script_set_attribute(attribute:"stig_severity", value:"II");
script_set_attribute(attribute:"thorough_tests", value:"true");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Windows");
script_copyright(english:"This script is Copyright (C) 2017-2022 Tenable Network Security, Inc.");
script_dependencies("win_chrome_browser_addons.nbin");
script_require_keys("SMB/Google_Chrome/Installed", "SMB/WindowsVersion");
script_require_ports(139, 445);
exit(0);
}
include("audit.inc");
include("datetime.inc");
include("misc_func.inc");
include("smb_func.inc");
include("smb_hotfixes.inc");
include("smb_reg_query.inc");
include("smb_hotfixes_fcheck.inc");
include("browser.inc");
include("json.inc");
addons = get_browser_addons(browser:"Chrome", type:"all", name:"Cisco WebEx Extension", exit_on_fail:TRUE);
ext_report = "";
report = "";
ver = NULL;
vuln = 0;
users = make_array();
hotfix_check_fversion_init();
foreach addon(addons["addons"])
{
if(users[addon['user']]) continue;
# Try to get active version from preferences
path = pregmatch(pattern:"(.*)Extensions.*", string:addon['path']);
path = path[1] + "Secure Preferences";
prefs = hotfix_get_file_contents(path:path);
if(prefs['error'] == 0)
{
prefs = json_read(prefs['data']);
ver = prefs[0]["extensions"]["settings"]["jlhmfgmfgeifomenelglieieghnjghma"]["manifest"]["version"];
users[addon['user']] = TRUE;
}
if(empty_or_null(ver))
{
if (report_paranoia < 2)
{
hotfix_check_fversion_end();
audit(AUDIT_PARANOID);
}
ver = chomp(addon['version']);
}
if(ver_compare(ver:ver, fix:"1.0.12", strict:FALSE) < 0)
{
vuln += 1;
ext_report += '\n' +
'\n User : ' + addon['user'] +
'\n Version : ' + addon['version'] +
'\n Update date : ' + addon['update_date'] +
'\n Path : ' + addon['path'] +
'\n';
}
}
hotfix_check_fversion_end();
if(vuln)
{
port = get_kb_item('SMB/transport');
if (!port) port = 445;
if(vuln > 1) user = "users have";
else user = "user has";
report += '\n' +
"The following " + user + " a vulnerable version of the Cisco WebEx Extension for Chrome installed :" +
ext_report +
'\n' +
"Fix : Upgrade to to Cisco WebEx Extension version 1.0.12 or later." +
'\n';
security_report_v4(severity:SECURITY_HOLE, port:port, extra:report);
}
else audit(AUDIT_INST_VER_NOT_VULN, "Cisco WebEx Extension for Chrome");
CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:M/Au:N/C:C/I:C/A:C
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
Percentile
91.5%