The remote Redhat Enterprise Linux 8 host has one or more packages installed that are affected by multiple vulnerabilities that have been acknowledged by the vendor but will not be patched.
Developer environment: Homoglyph characters can lead to trojan source attack (CVE-2021-42694)
An issue was discovered in the Bidirectional Algorithm in the Unicode Specification through 14.0. It permits the visual reordering of characters via control sequences, which can be used to craft source code that renders different logic than the logical ordering of tokens ingested by compilers and interpreters.
Adversaries can leverage this to encode source code for compilers accepting Unicode such that targeted vulnerabilities are introduced invisibly to human reviewers. NOTE: the Unicode Consortium offers the following alternative approach to presenting this concern. An issue is noted in the nature of international text that can affect applications that implement support for The Unicode Standard and the Unicode Bidirectional Algorithm (all versions). Due to text display behavior when text includes left-to- right and right-to-left characters, the visual order of tokens may be different from their logical order.
Additionally, control characters needed to fully support the requirements of bidirectional text can further obfuscate the logical order of tokens. Unless mitigated, an adversary could craft source code such that the ordering of tokens perceived by human reviewers does not match what will be processed by a compiler/interpreter/etc. The Unicode Consortium has documented this class of vulnerability in its document, Unicode Technical Report #36, Unicode Security Considerations. The Unicode Consortium also provides guidance on mitigations for this class of issues in Unicode Technical Standard #39, Unicode Security Mechanisms, and in Unicode Standard Annex #31, Unicode Identifier and Pattern Syntax. Also, the BIDI specification allows applications to tailor the implementation in ways that can mitigate misleading visual reordering in program text; see HL4 in Unicode Standard Annex #9, Unicode Bidirectional Algorithm.
(CVE-2021-42574)
Note that Nessus has not tested for these issues but has instead relied on the package manager’s report that the package is installed.
#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Red Hat Security Advisory developer_environment. The text
# itself is copyright (C) Red Hat, Inc.
##
include('compat.inc');
if (description)
{
script_id(196173);
script_version("1.0");
script_set_attribute(attribute:"plugin_modification_date", value:"2024/05/11");
script_cve_id("CVE-2021-42574", "CVE-2021-42694");
script_name(english:"RHEL 8 : developer_environment (Unpatched Vulnerability)");
script_set_attribute(attribute:"synopsis", value:
"The remote Red Hat 8 host is affected by multiple vulnerabilities that will not be patched.");
script_set_attribute(attribute:"description", value:
"The remote Redhat Enterprise Linux 8 host has one or more packages installed that are affected by multiple
vulnerabilities that have been acknowledged by the vendor but will not be patched.
- Developer environment: Homoglyph characters can lead to trojan source attack (CVE-2021-42694)
- An issue was discovered in the Bidirectional Algorithm in the Unicode Specification through 14.0. It
permits the visual reordering of characters via control sequences, which can be used to craft source code
that renders different logic than the logical ordering of tokens ingested by compilers and interpreters.
Adversaries can leverage this to encode source code for compilers accepting Unicode such that targeted
vulnerabilities are introduced invisibly to human reviewers. NOTE: the Unicode Consortium offers the
following alternative approach to presenting this concern. An issue is noted in the nature of
international text that can affect applications that implement support for The Unicode Standard and the
Unicode Bidirectional Algorithm (all versions). Due to text display behavior when text includes left-to-
right and right-to-left characters, the visual order of tokens may be different from their logical order.
Additionally, control characters needed to fully support the requirements of bidirectional text can
further obfuscate the logical order of tokens. Unless mitigated, an adversary could craft source code such
that the ordering of tokens perceived by human reviewers does not match what will be processed by a
compiler/interpreter/etc. The Unicode Consortium has documented this class of vulnerability in its
document, Unicode Technical Report #36, Unicode Security Considerations. The Unicode Consortium also
provides guidance on mitigations for this class of issues in Unicode Technical Standard #39, Unicode
Security Mechanisms, and in Unicode Standard Annex #31, Unicode Identifier and Pattern Syntax. Also, the
BIDI specification allows applications to tailor the implementation in ways that can mitigate misleading
visual reordering in program text; see HL4 in Unicode Standard Annex #9, Unicode Bidirectional Algorithm.
(CVE-2021-42574)
Note that Nessus has not tested for these issues but has instead relied on the package manager's report that the package
is installed.");
script_set_attribute(attribute:"solution", value:
"The vendor has acknowledged the vulnerabilities but no solution has been provided. Refer to the vendor for remediation
guidance.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:P/I:P/A:P");
script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:R/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-2021-42694");
script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
script_set_attribute(attribute:"exploit_available", value:"true");
script_set_attribute(attribute:"vendor_unpatched", value:"true");
script_set_attribute(attribute:"vuln_publication_date", value:"2021/10/28");
script_set_attribute(attribute:"plugin_publication_date", value:"2024/05/11");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7");
script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:8");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gcc");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gcc-toolset-9-annobin");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gcc-toolset-9-binutils");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gcc-toolset-9-gcc");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:golang");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:mingw-binutils");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Red Hat Local Security Checks");
script_copyright(english:"This script is Copyright (C) 2024 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("ssh_get_info.nasl", "redhat_repos.nasl");
script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list", "Host/cpu");
exit(0);
}
include('rpm.inc');
include('rhel.inc');
if (!get_kb_item("global_settings/vendor_unpatched"))
exit(0, "Unpatched Vulnerabilities Detection not active.");
if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/RedHat/release');
if (isnull(os_release) || 'Red Hat' >!< os_release) audit(AUDIT_OS_NOT, 'Red Hat');
var os_ver = pregmatch(pattern: "Red Hat Enterprise Linux.*release ([0-9]+(\.[0-9]+)?)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Red Hat');
os_ver = os_ver[1];
if (!rhel_check_release(operator: 'ge', os_version: os_ver, rhel_version: '8')) audit(AUDIT_OS_NOT, 'Red Hat 8.x', 'Red Hat ' + os_ver);
if (!get_kb_item('Host/RedHat/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);
var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu && 'ppc' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Red Hat', cpu);
var constraints = [
{
'pkgs': [
{'reference':'gcc', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'unpatched_pkg':'gcc', 'cves':['CVE-2021-42694']},
{'reference':'gcc-toolset-9-annobin', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'unpatched_pkg':'gcc-toolset-9-annobin', 'cves':['CVE-2021-42574']},
{'reference':'gcc-toolset-9-binutils', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'unpatched_pkg':'gcc-toolset-9-binutils', 'cves':['CVE-2021-42574']},
{'reference':'gcc-toolset-9-gcc', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'unpatched_pkg':'gcc-toolset-9-gcc', 'cves':['CVE-2021-42574']},
{'reference':'golang', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'unpatched_pkg':'golang', 'cves':['CVE-2021-42574']},
{'reference':'mingw-binutils', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'unpatched_pkg':'mingw-binutils', 'cves':['CVE-2021-42574']}
]
}
];
var flag = 0;
foreach var constraint_array ( constraints ) {
var repo_relative_urls = NULL;
var enterprise_linux_flag = rhel_repo_urls_has_content_dist_rhel(repo_urls:repo_relative_urls);
foreach var pkg ( constraint_array['pkgs'] ) {
var unpatched_pkg = NULL;
var _release = NULL;
var sp = NULL;
var el_string = NULL;
var rpm_spec_vers_cmp = NULL;
var exists_check = NULL;
var cves = NULL;
if (!empty_or_null(pkg['unpatched_pkg'])) unpatched_pkg = pkg['unpatched_pkg'];
if (!empty_or_null(pkg['release'])) _release = 'RHEL' + pkg['release'];
if (!empty_or_null(pkg['sp'])) sp = pkg['sp'];
if (!empty_or_null(pkg['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = pkg['rpm_spec_vers_cmp'];
if (!empty_or_null(pkg['exists_check'])) exists_check = pkg['exists_check'];
if (!empty_or_null(pkg['cves'])) cves = pkg['cves'];
if (unpatched_pkg &&
_release &&
(!exists_check || rpm_exists(release:_release, rpm:exists_check)) &&
unpatched_package_exists(release:_release, package:unpatched_pkg, cves: cves)) flag++;
}
}
if (flag)
{
var extra = NULL;
security_report_v4(
port : 0,
severity : SECURITY_WARNING,
extra : unpatched_packages_report()
);
exit(0);
}
else
{
var tested = pkg_tests_get();
if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'gcc / gcc-toolset-9-annobin / gcc-toolset-9-binutils / etc');
}
Vendor | Product | Version | CPE |
---|---|---|---|
redhat | enterprise_linux | 7 | cpe:/o:redhat:enterprise_linux:7 |
redhat | enterprise_linux | 8 | cpe:/o:redhat:enterprise_linux:8 |
redhat | enterprise_linux | gcc | p-cpe:/a:redhat:enterprise_linux:gcc |
redhat | enterprise_linux | gcc-toolset-9-annobin | p-cpe:/a:redhat:enterprise_linux:gcc-toolset-9-annobin |
redhat | enterprise_linux | gcc-toolset-9-binutils | p-cpe:/a:redhat:enterprise_linux:gcc-toolset-9-binutils |
redhat | enterprise_linux | gcc-toolset-9-gcc | p-cpe:/a:redhat:enterprise_linux:gcc-toolset-9-gcc |
redhat | enterprise_linux | golang | p-cpe:/a:redhat:enterprise_linux:golang |
redhat | enterprise_linux | mingw-binutils | p-cpe:/a:redhat:enterprise_linux:mingw-binutils |