CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:L/Au:N/C:N/I:P/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
AI Score
Confidence
High
EPSS
Percentile
79.7%
According to its banner, the version of OpenSSH running on the remote host is prior to 7.6. It is, therefore, affected by a file creation restriction bypass vulnerability related to the ‘process_open’ function in the file ‘sftp-server.c’ that allows authenticated users to create zero-length files regardless of configuration.
Note that Nessus has not tested for these issues but has instead relied only on the application’s self-reported version number.
#
# (C) Tenable, Inc.
#
include("compat.inc");
if (description)
{
script_id(103781);
script_version("1.9");
script_set_attribute(attribute:"plugin_modification_date", value:"2024/03/27");
script_cve_id("CVE-2017-15906");
script_bugtraq_id(101552);
script_name(english:"OpenSSH < 7.6");
script_summary(english:"Checks the OpenSSH banner version.");
script_set_attribute(attribute:"synopsis", value:
"The SSH server running on the remote host is affected by a
file creation restriction bypass vulnerability.");
script_set_attribute(attribute:"description", value:
"According to its banner, the version of OpenSSH running on the remote
host is prior to 7.6. It is, therefore, affected by a file creation
restriction bypass vulnerability related to the 'process_open'
function in the file 'sftp-server.c' that allows authenticated users
to create zero-length files regardless of configuration.
Note that Nessus has not tested for these issues but has instead
relied only on the application's self-reported version number.");
# https://github.com/openbsd/src/commit/a6981567e8e215acc1ef690c8dbb30f2d9b00a19#diff-8b99aa649abd796be7cc465d6f0a2f96
script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?09ca048b");
# https://github.com/openssh/openssh-portable/commit/4d827f0d75a53d3952288ab882efbddea7ffadfe#diff-066c02faff81900a14a658dae29b3e15
script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?96a8ea52");
script_set_attribute(attribute:"see_also", value:"http://www.openssh.com/txt/release-7.6");
script_set_attribute(attribute:"solution", value:
"Upgrade to OpenSSH version 7.6 or later.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N");
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:N/S:U/C:N/I:L/A:N");
script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2017-15906");
script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
script_set_attribute(attribute:"exploit_available", value:"false");
script_set_attribute(attribute:"vuln_publication_date", value:"2017/10/04");
script_set_attribute(attribute:"patch_publication_date", value:"2017/10/03");
script_set_attribute(attribute:"plugin_publication_date", value:"2017/10/11");
script_set_attribute(attribute:"plugin_type", value:"remote");
script_set_attribute(attribute:"cpe", value:"cpe:/a:openbsd:openssh");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Misc.");
script_copyright(english:"This script is Copyright (C) 2023-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("openssh_detect.nbin");
script_require_keys("installed_sw/OpenSSH");
script_require_ports("Services/ssh", 22);
exit(0);
}
include('backport.inc');
include('vcf.inc');
include('vcf_extras.inc');
var port = get_service(svc:'ssh', default:22, exit_on_fail:TRUE);
var app_info = vcf::openssh::get_app_info(app:'OpenSSH', port:port);
vcf::check_all_backporting(app_info:app_info);
var constraints = [
{'fixed_version': '7.6'}
];
vcf::openssh::check_version_and_report(app_info:app_info, constraints:constraints, severity:SECURITY_WARNING);
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:L/Au:N/C:N/I:P/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
AI Score
Confidence
High
EPSS
Percentile
79.7%