Xen Project Speculative Execution Side Channel Vulnerability (XSA-273) (Foreshadow)

#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(112159);
  script_version("1.6");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/06/03");

  script_cve_id("CVE-2018-3620", "CVE-2018-3646");
  script_bugtraq_id(105080);
  script_xref(name:"IAVB", value:"2018-B-0111-S");

  script_name(english:"Xen Project Speculative Execution Side Channel Vulnerability (XSA-273) (Foreshadow)");
  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 a speculative execution
side channel attack known as L1 Terminal Fault (L1TF). An attacker
who successfully exploited L1TF may be able to read privileged data
across trust boundaries.

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-273.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:M/Au:N/C:C/I:N/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/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-2018-3620");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"in_the_news", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/08/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/08/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/08/28");

  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) 2018-2021 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);

fixes['4.6']['fixed_ver']           = '4.6.6';
fixes['4.6']['fixed_ver_display']   = '4.6.6 (changeset ef1b648)';
fixes['4.6']['affected_ver_regex']  = '^4\\.6\\.';
fixes['4.6']['affected_changesets'] = make_list("ad9cfb4", "e333ed7",
  "200bae4", "e1b03b0", "1ecb0d4", "4b12b44", "c932ff1", "b2449f5",
  "1fa97ce", "3bcdcd8", "17b522c", "2b1e6a4", "0840ade", "753f8d9",
  "14402dc", "45f6a27", "4c8d9f8", "1840f82", "a80ce17", "7d98594",
  "f30c9b6", "a1b8d86", "ff1d0b6", "3bd7cf6", "55c7bd6", "98d7948",
  "e0981f6", "91cf29f", "a0c3f80", "cf7d9d1", "170c48b", "c39cd00",
  "2d69b6d", "03ba272", "1fa0ecb", "598a375", "b7b7c4d", "ba7d011",
  "a544804", "2642b56", "03938ba", "542f711", "90dc163", "61a9fc5",
  "a671bd6", "365ecff", "237236a", "aa5a889", "3e3c11b", "8a2e1db",
  "cb0230a", "4336ffa", "3df7d47", "5ccba18", "991dd4c", "331a1af",
  "035c96f", "bfe8f3e", "4f0509d", "2f99d68", "0d3904f", "342a02f",
  "2d8e87e", "ac659af", "c1be09e", "e7b723b", "cd5232a", "f9f9634",
  "6981351", "12b9fca", "916ef0d", "055abe4", "c4333f5", "3d6970d",
  "a0db1f2", "6a74f4e", "5278a9a", "c53663a", "c5339c5", "3b96676",
  "2f3cde3", "acd8661", "5ddc3f8", "927aca7", "b4b553d", "b766574",
  "10898d7", "0b38930", "33f70b8", "cf03d32", "525c381", "4c1e2d3",
  "021009e", "4972c38", "bd461fc", "c9c1bb6", "0fbf30a", "7e20b9b",
  "d1618f4", "9d534c1", "dbb3553", "e54a8c6", "8005ed3", "9a852e0",
  "d779cc1", "c93bcf9", "15adcf3", "d7b8190", "2b1457f", "a357880",
  "ee23fcc", "5651015", "225e9c7", "3c70619", "1222333", "75bdd69",
  "8994cf3", "642c603", "c25ea9a", "feba571", "0163087", "44c2666",
  "db743b0", "41a5cce", "4e1b9e9", "4d21549", "ff4800c", "2613a1b",
  "8335c8a", "ab20c5c", "9089da9", "8edfc82", "af5b61a", "ec05090",
  "75263f7", "f7e273a", "03c7d2c", "9ce1a71", "a735c7a", "44ad7f6",
  "91dc902", "a065841", "c6e9e60", "f94c11d", "45ddc4e", "1ca93b7",
  "8c0c36e", "6e43623", "47d3e73", "ea80245", "37bb22b", "9b0c2a2",
  "8d3fe28", "be63d66", "9454e30", "aad5a67", "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']           = '4.7.6';
fixes['4.7']['fixed_ver_display']   = '4.7.6 (changeset 3f7b4ec)';
fixes['4.7']['affected_ver_regex']  = '^4\\.7\\.';
fixes['4.7']['affected_changesets'] = make_list("7ba1c7d", "87d5aa4",
  "9b8375a", "da93914", "0aa4696", "f05a33e", "f440b31", "1a90803",
  "0abc1ae", "1fdb25a", "c9641d4", "61c4360", "df66c1c", "59732fd",
  "3f7fd2b", "bcbd8b9", "dfee811", "95ff4e1", "ded2a37", "87dba80",
  "fe028e6", "a51e6a3", "0e66281", "51d9780", "91ca84c", "bce2dd6",
  "fa807e2", "97aff08", "e90e243", "c0e854b", "9858a1f", "a404136",
  "dc111e9", "0873699", "280a556");

fixes['4.8']['fixed_ver']           = '4.8.5';
fixes['4.8']['fixed_ver_display']   = '4.8.5-pre (changeset d95b5bb)';
fixes['4.8']['affected_ver_regex']  = '^4\\.8\\.';
fixes['4.8']['affected_changesets'] = make_list("565de91", "1c6c2de",
  "1f56fba", "5464d5f", "9e7d5e2", "7849d13", "e819108", "fe78829",
  "28fc483", "712082d", "ed6fcdb", "0406164", "e3d0ce3", "c00fabc",
  "3478439", "b81b74a", "b289403", "47fbc6e", "ee7bcea", "df5bbf7",
  "d96893f", "15508b3", "790ed15", "d838957", "aa45015", "b149b06",
  "c117d09", "e343ee8", "5566272", "f049cd6", "6dc0bc5", "37a1b4a",
  "f6a31ed", "08eda97", "96bf2db", "23975f5", "f3b0cdb", "f5ef10d",
  "de172b0", "3686d09", "4aec0c7");

fixes['4.9']['fixed_ver']           = '4.9.3';
fixes['4.9']['fixed_ver_display']   = '4.9.3-pre (changeset 14f90aa)';
fixes['4.9']['affected_ver_regex']  = '^4\\.9\\.';
fixes['4.9']['affected_changesets'] = make_list("c95088f", "cac6aa0",
  "fd86a3c", "e06752e", "f73c777", "a5d7667", "4704d59", "3ad78aa",
  "a060b69", "ac3d572", "8231311", "ab34a43", "023da62", "01b624b",
  "c4fda1d", "946badc", "db356a4", "0c9baf6", "c847824", "66a3e68",
  "ec32158", "6522c1c", "284c601", "3d2dc31", "a1b223b", "a894c9d",
  "d866881", "819e114", "c6055c5", "cc15a7b", "15124d9", "7f4a82d",
  "e40bfc1", "53b22ad", "ec3030f", "84dd174", "c4d86c6", "a6ac51a",
  "514785c", "f904bdd", "036006f", "f5c692a", "612ff3c", "555ef37",
  "e76d0f7", "19f4f87", "c4cb7d3", "8cdaac2", "7fbbedd", "46863c6",
  "041844b", "0a9c2bd", "5d92007", "c257e35", "ad08a1b", "c50b1f6",
  "238007d", "0b1904c", "859fc55", "1c6b8f2", "f51d368", "8689cd1",
  "fc72347", "27b0dcd", "8d874a8", "1284b90", "12259ff", "516ac8a",
  "ed217c9", "11eb72e", "3f85ebb", "1ed3466", "37c3cb4", "2aca1d7",
  "22a6433", "8a29d83", "14a2ad6", "c6d09b2", "e5de993", "c2029b4",
  "5633efa", "13cb0c2", "da140c6", "39ab89d", "a29695c", "74fa955",
  "b3277ca", "cf264eb", "809d543", "002ea4d", "1f183b5", "150cdd9",
  "f7889b3", "903f2f6", "4bbed1c", "2303a9d", "d674b6e", "52fa2f7",
  "62bd851", "c06ec81", "dbb06d3", "24fa3fa", "b9b5a03", "35a71c6",
  "b844573", "48dd543", "7866e11", "db7accf", "921bff4", "c147505",
  "dc527ff", "781e23a", "72ca580", "47d41f6", "7a59015", "259bee9",
  "6d4c4f0", "3e010f5");

fixes['4.10']['fixed_ver']           = '4.10.2';
fixes['4.10']['fixed_ver_display']   = '4.10.2-pre (changeset 13e85a6)';
fixes['4.10']['affected_ver_regex']  = '^4\\.10\\.';
fixes['4.10']['affected_changesets'] = make_list("fac0731", "ed93304",
  "ef71d13", "80dd3f5", "c67a8b8", "85d133b", "d46374d", "614fd25",
  "684fb8c", "56d5138", "924a5ee", "5fd0bb3", "9e7ee94", "0de39f3",
  "6504045", "b4d6690", "09b6924", "2450f34", "227da39", "07a9be7",
  "dcca8f0", "8af1a79", "93017a6", "6e57d28", "87c83af", "b07c76f",
  "541a105", "6f6207f", "6feafd8", "01eb262", "512d3e7", "74f437f",
  "371149b", "3607213", "7145525", "498716e", "fab92fc", "bc1289f",
  "4ccf397", "381fdae", "d976fe5", "a645331", "c220240", "78a86a7",
  "6e0e45a", "b81a8bf", "de578bc", "3bd7966", "dd07d3e", "b5e9f1e",
  "e0da0d9", "2308158", "b2444d2", "42219af", "1d5a9ec", "eeb1576",
  "4b9dc6d", "52447b3", "7b35e78", "8d48204", "b3a7f2f", "fb78102",
  "245eaee", "18833a8", "72e5b16", "27a4161", "23114db", "6300cdd",
  "2a0913e", "daaf3dd", "c2b84e7", "908ddbb", "c75bbf1", "e9dc0a6",
  "470daef", "c9fdfbb", "49aebf4", "48ad1ab", "98a285c", "cb2a83f",
  "51b7b5d", "840d683", "ec50d21", "a035518", "8342e3f", "aaf66de",
  "7e21b75", "f155f55", "3a903b3", "2e2f337", "850e5ad", "13fa2a4",
  "ade8f98", "a7f8880", "3bb756b", "1aa6305", "d93ae63", "6b8d820", "f253feb");

fixes['4.11']['fixed_ver']           = '4.11.1';
fixes['4.11']['fixed_ver_display']   = '4.11.1-pre (changeset d757c29)';
fixes['4.11']['affected_ver_regex']  = '^4\\.11\\.';
fixes['4.11']['affected_changesets'] = make_list("6c7d074", "2a47c75",
  "007752f", "fb78137", "665e768", "f4a049e", "02d2c66", "57483c0",
  "d044f6c", "e6441a8", "48fb482", "fa79f9e", "1d32c21", "7b420e8",
  "8b35b97", "cfdd4e8", "218d403", "b52017c", "52b8f9a", "935e9c4",
  "61cc876", "4254e98", "6fe9726", "33ced72", "7de2155", "06d2a76",
  "543027c", "037fe82", "353edf1", "75313e4", "5908b48", "bd51a64",
  "0a2016c", "b53e0de", "a44cf0c", "ac35e05", "10c5482", "4bdeedb",
  "da33530", "e932371", "1fd87ba");

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_WARNING);