7.2 High
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:C/I:C/A:C
8.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
0.001 Low
EPSS
Percentile
42.3%
According to its self-reported version number, the Xen hypervisor installed on the remote host is affected by an unspecified flaw that is triggered when, as a new CPU is brought online, it copies certain selector fields from CPU0’s Interrupt Descriptor Table (IDT) while CPU0 is in HVM context. This may result in incorrect values being copied, allowing an attacker on the guest to cause a denial of service or gain elevated privileges on the host.
Note that Nessus has checked the changeset versions based on the xen.git change log. Nessus did not check guest hardware configurations or if patches were applied manually to the source code before a recompile and reinstall.
#
# (C) Tenable Network Security, Inc.
#
include("compat.inc");
if (description)
{
script_id(103979);
script_version("1.7");
script_set_attribute(attribute:"plugin_modification_date", value:"2021/06/03");
script_cve_id(
"CVE-2017-15588",
"CVE-2017-15589",
"CVE-2017-15590",
"CVE-2017-15591",
"CVE-2017-15592",
"CVE-2017-15593",
"CVE-2017-15594",
"CVE-2017-15595",
"CVE-2017-15596"
);
script_bugtraq_id(101490, 101496, 101500);
script_xref(name:"IAVB", value:"2017-B-0142-S");
script_name(english:"Xen Hypervisor New CPU Interrupt Descriptor Table (IDT) Copy Handling Guest-to-Host Privilege Escalation (XSA-244)");
script_summary(english:"Checks 'xl info' output for the Xen hypervisor version.");
script_set_attribute(attribute:"synopsis", value:
"The remote Xen hypervisor installation is missing a security update.");
script_set_attribute(attribute:"description", value:
"According to its self-reported version number, the Xen hypervisor
installed on the remote host is affected by an unspecified flaw that
is triggered when, as a new CPU is brought online, it copies certain
selector fields from CPU0's Interrupt Descriptor Table (IDT) while
CPU0 is in HVM context. This may result in incorrect values being
copied, allowing an attacker on the guest to cause a denial of
service or gain elevated privileges on the host.
Note that Nessus has checked the changeset versions based on the
xen.git change log. Nessus did not check guest hardware configurations
or if patches were applied manually to the source code before a
recompile and reinstall.");
script_set_attribute(attribute:"see_also", value:"http://xenbits.xen.org/xsa/advisory-244.html");
script_set_attribute(attribute:"see_also", value:"https://xenbits.xen.org/gitweb/?p=xen.git;a=summary");
script_set_attribute(attribute:"solution", value:
"Apply the appropriate patch according to the vendor advisory.");
script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C");
script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H");
script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2017-15595");
script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
script_set_attribute(attribute:"exploit_available", value:"true");
script_set_attribute(attribute:"vuln_publication_date", value:"2017/10/12");
script_set_attribute(attribute:"patch_publication_date", value:"2017/10/12");
script_set_attribute(attribute:"plugin_publication_date", value:"2017/10/19");
script_set_attribute(attribute:"potential_vulnerability", value:"true");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"cpe:/o:xen:xen");
script_set_attribute(attribute:"stig_severity", value:"I");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Misc.");
script_copyright(english:"This script is Copyright (C) 2017-2021 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("xen_server_detect.nbin");
script_require_keys("installed_sw/Xen Hypervisor", "Settings/ParanoidReport");
exit(0);
}
include("audit.inc");
include("global_settings.inc");
include("install_func.inc");
include("misc_func.inc");
app_name = "Xen Hypervisor";
install = get_single_install(app_name:app_name);
if (report_paranoia < 2) audit(AUDIT_PARANOID);
version = install['version'];
display_version = install['display_version'];
path = install['path'];
managed_status = install['Managed status'];
changeset = install['Changeset'];
if (!empty_or_null(changeset))
display_version += " (changeset " + changeset + ")";
# Installations that are vendor-managed are handled by OS-specific local package checks
if (managed_status == "managed")
audit(AUDIT_INST_PATH_NOT_VULN, app_name, display_version, path);
# XSA-244
fixes['4.5']['fixed_ver'] = '4.5.5';
fixes['4.5']['fixed_ver_display'] = '4.5.5 (changeset 77666b6)';
fixes['4.5']['affected_ver_regex'] = '^4\\.5\\.';
fixes['4.5']['affected_changesets'] = make_list("bbeb763", "5fdf16f",
"0e9967d", "da4f24d", "b7582ac", "196371c", "7afc8ad", "72c107b",
"5659aa5", "a224de6", "6442fa9", "db487a6", "709230f", "83724d9",
"04b8c4c", "0b2ceae", "e3f0768", "d5a5231", "c5b0fe5", "136ff4e",
"42c8ba5", "d38489d", "df59014", "3217129", "4964e86", "c079597",
"6ec173b", "a373456", "0780e81", "e5ef76d", "25eaa86", "ae02360",
"5597df9", "c5de05e", "773094e", "e39a248", "7b3712a", "be35327",
"8825df1", "d7e3725", "6eb61e4", "b1fcfed", "5779d6a", "afdd77e",
"c18367a", "7b7fd80", "b30e165", "62ef9b2", "8071724", "235b5d5",
"a28b99d", "ff294fc", "bc01e2d", "da50922", "386cc94", "139960f",
"ec3ddd6", "988929a", "1c48dff", "20d4248", "9610422", "cd76cd3",
"455fd66", "b820c31", "ac3d8bc", "cde86fc", "1678521", "83cb2db",
"43d06ef", "2b17bf4", "1a2bda5", "0bd7faf", "e3426e2", "37281bc",
"27be856", "bdf3ef1", "cc325c0", "8e7b84d", "387b8ae", "34fbae7",
"1530da2", "274a1f6", "b679cfa", "877b760", "cfe165d", "84e4e56",
"e4ae4b0");
fixes['4.6']['fixed_ver'] = '4.6.6';
fixes['4.6']['fixed_ver_display'] = '4.6.6 (changeset aad5a67)';
fixes['4.6']['affected_ver_regex'] = '^4\\.6\\.';
fixes['4.6']['affected_changesets'] = make_list("d8b0ebf", "f0208a4",
"42b2c82", "57318e1", "9f22d72", "e0353b4", "76f1549", "9bac910",
"c7a43e3", "913d4f8", "c5881c5", "b0239cd", "78fd0c3", "9079e0d",
"1658a87", "22b6dfa", "a8cd231", "629eddd", "64c03bb", "b4660b4",
"1ac8162", "747df3c", "5ae011e", "f974d32", "3300ad3", "d708b69");
fixes['4.7']['fixed_ver'] = '4.7.4';
fixes['4.7']['fixed_ver_display'] = '4.7.4-pre (changeset c10dc54)';
fixes['4.7']['affected_ver_regex'] = '^4\\.7\\.';
fixes['4.7']['affected_changesets'] = make_list("8cd1258", "1d01ddc",
"5ca7d11", "ebd47d4", "6a6a339", "e61be54", "e3f7a64", "957ad23",
"b1ae705", "3add76f", "314a8fc", "d6aad63", "7c99633", "145c18d",
"c3fa5cd", "487f8f9", "ffcfc40", "c7783d9", "3331050", "83966a3",
"a67b223", "68dbba2", "2728470", "dea68ed", "9d12253", "73d7bc5",
"b704b1a", "ca4ef7b", "ece330a", "3d63ebc", "30d50f8", "2dc3cdb",
"5151257", "c9f3ca0", "e873251", "8aebf85", "c362cde", "fece08a");
fixes['4.8']['fixed_ver'] = '4.8.3';
fixes['4.8']['fixed_ver_display'] = '4.8.3-pre (changeset bdc2ae6)';
fixes['4.8']['affected_ver_regex'] = '^4\\.8\\.';
fixes['4.8']['affected_changesets'] = make_list("96e6364", "1a8ad09",
"df89197", "c4f969d", "b1f3f1d", "7251c06", "1960ca8", "866cfa1",
"ddd6e41", "370cc9a", "39e3024", "9f092f5", "667f70e", "2116fec",
"1a535c3", "ee3fc24", "d623d82", "dda458c", "c642b12", "80d7ef3",
"ff4f60a", "36898eb", "4d7ccae", "e574046", "90dafa4", "c020cf2");
fixes['4.9']['fixed_ver'] = '4.9.1';
fixes['4.9']['fixed_ver_display'] = '4.9.1-pre (changeset de38e28)';
fixes['4.9']['affected_ver_regex'] = '^4\\.9\\.';
fixes['4.9']['affected_changesets'] = make_list("7fe0a24", "a2af47d",
"61a2d31", "c2b0a92", "d842630", "ef61bcf", "44ceb19", "ae45442",
"784afd9", "22032b2", "58da67f", "d1b64cc", "9cde7a8", "1cdcb36",
"84c039e", "b244ac9", "612044a", "e8fd372", "a568e25", "8fef83e",
"478e40c", "22ea731", "e7703a2", "91ded3b", "2cc3d32", "79775f5",
"43cb0c4", "4821228", "d23bcc5", "308654c", "6fd84b3", "89b36cc",
"a9ecd60", "798f6c9", "6508278", "5587d9a", "527fc5c", "5ff1de3",
"692ed82", "9bf14bb", "c57b1f9", "6b147fd", "0e186e3", "afc5ebf",
"266fc0e", "4698106", "f4f02f1", "0fada05", "ab4eb6c", "b29ecc7",
"a11d14b", "107401e", "1b7834a");
fix = NULL;
foreach ver_branch (keys(fixes))
{
if (version =~ fixes[ver_branch]['affected_ver_regex'])
{
ret = ver_compare(ver:version, fix:fixes[ver_branch]['fixed_ver']);
if (ret < 0)
fix = fixes[ver_branch]['fixed_ver_display'];
else if (ret == 0)
{
if (empty_or_null(changeset))
fix = fixes[ver_branch]['fixed_ver_display'];
else
foreach affected_changeset (fixes[ver_branch]['affected_changesets'])
if (changeset == affected_changeset)
fix = fixes[ver_branch]['fixed_ver_display'];
}
}
}
if (empty_or_null(fix))
audit(AUDIT_INST_PATH_NOT_VULN, app_name, display_version, path);
items = make_array("Installed version", display_version,
"Fixed version", fix,
"Path", path);
order = make_list("Path", "Installed version", "Fixed version");
report = report_items_str(report_items:items, ordered_fields:order) + '\n';
security_report_v4(port:0, extra:report, severity:SECURITY_HOLE);
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-15588
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-15589
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-15590
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-15591
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-15592
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-15593
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-15594
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-15595
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-15596
xenbits.xen.org/xsa/advisory-244.html
xenbits.xen.org/gitweb/?p=xen.git;a=summary
7.2 High
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:C/I:C/A:C
8.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
0.001 Low
EPSS
Percentile
42.3%