Huawei EulerOS: Security Advisory for grub2 (EulerOS-SA-2021-1601)

# SPDX-FileCopyrightText: 2021 Greenbone AG
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-only

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.1.2.2021.1601");
  script_cve_id("CVE-2020-10713", "CVE-2020-14308", "CVE-2020-14309", "CVE-2020-14310", "CVE-2020-14311", "CVE-2020-15706", "CVE-2020-15707");
  script_tag(name:"creation_date", value:"2021-03-12 07:22:32 +0000 (Fri, 12 Mar 2021)");
  script_version("2024-02-05T14:36:56+0000");
  script_tag(name:"last_modification", value:"2024-02-05 14:36:56 +0000 (Mon, 05 Feb 2024)");
  script_tag(name:"cvss_base", value:"4.6");
  script_tag(name:"cvss_base_vector", value:"AV:L/AC:L/Au:N/C:P/I:P/A:P");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2020-08-05 14:34:24 +0000 (Wed, 05 Aug 2020)");

  script_name("Huawei EulerOS: Security Advisory for grub2 (EulerOS-SA-2021-1601)");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2021 Greenbone AG");
  script_family("Huawei EulerOS Local Security Checks");
  script_dependencies("gb_huawei_euleros_consolidation.nasl");
  script_mandatory_keys("ssh/login/euleros", "ssh/login/rpms", re:"ssh/login/release=EULEROSVIRT\-2\.9\.1");

  script_xref(name:"Advisory-ID", value:"EulerOS-SA-2021-1601");
  script_xref(name:"URL", value:"https://developer.huaweicloud.com/intl/en-us/euleros/securitydetail.html?secId=EulerOS-SA-2021-1601");

  script_tag(name:"summary", value:"The remote host is missing an update for the Huawei EulerOS 'grub2' package(s) announced via the EulerOS-SA-2021-1601 advisory.");

  script_tag(name:"vuldetect", value:"Checks if a vulnerable package version is present on the target host.");

  script_tag(name:"insight", value:"A flaw was found in grub2, prior to version 2.06. An attacker may use the GRUB 2 flaw to hijack and tamper the GRUB verification process. This flaw also allows the bypass of Secure Boot protections. In order to load an untrusted or modified kernel, an attacker would first need to establish access to the system such as gaining physical access, obtain the ability to alter a pxe-boot network, or have remote access to a networked system with root access. With this access, an attacker could then craft a string to cause a buffer overflow by injecting a malicious payload that leads to arbitrary code execution within GRUB. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.(CVE-2020-10713)

Integer overflows were discovered in the functions grub_cmd_initrd and grub_initrd_init in the efilinux component of GRUB2, as shipped in Debian, Red Hat, and Ubuntu (the functionality is not included in GRUB2 upstream), leading to a heap-based buffer overflow. These could be triggered by an extremely large number of arguments to the initrd command on 32-bit architectures, or a crafted filesystem with very large files on any architecture. An attacker could use this to execute arbitrary code and bypass UEFI Secure Boot restrictions. This issue affects GRUB2 version 2.04 and prior versions.(CVE-2020-15707)

GRUB2 contains a race condition in grub_script_function_create() leading to a use-after-free vulnerability which can be triggered by redefining a function whilst the same function is already executing, leading to arbitrary code execution and secure boot restriction bypass. This issue affects GRUB2 version 2.04 and prior versions.(CVE-2020-15706)

There is an issue with grub2 before version 2.06 while handling symlink on ext filesystems. A filesystem containing a symbolic link with an inode size of UINT32_MAX causes an arithmetic overflow leading to a zero-sized memory allocation with subsequent heap-based buffer overflow.(CVE-2020-14311)

There is an issue on grub2 before version 2.06 at function read_section_as_string(). It expects a font name to be at max UINT32_MAX - 1 length in bytes but it doesn't verify it before proceed with buffer allocation to read the value from the font value. An attacker may leverage that by crafting a malicious font file which has a name with UINT32_MAX, leading to read_section_as_string() to an arithmetic overflow, zero-sized allocation and further heap-based buffer overflow.(CVE-2020-14310)

There's an issue with grub2 in all versions before 2.06 when handling squashfs filesystems containing a symbolic link with name length of UINT32 bytes in size. The name size leads to an arithmetic overflow leading to a zero-size allocation further causing a heap-based buffer overflow with attacker controlled data.(CVE-2020-14309)

In grub2 versions before 2.06 the grub memory allocator doesn't check for ... [Please see the references for more information on the vulnerabilities]");

  script_tag(name:"affected", value:"'grub2' package(s) on Huawei EulerOS Virtualization release 2.9.1.");

  script_tag(name:"solution", value:"Please install the updated package(s).");

  script_tag(name:"solution_type", value:"VendorFix");
  script_tag(name:"qod_type", value:"package");

  exit(0);
}

include("revisions-lib.inc");
include("pkg-lib-rpm.inc");

release = rpm_get_ssh_release();
if(!release)
  exit(0);

res = "";
report = "";

if(release == "EULEROSVIRT-2.9.1") {

  if(!isnull(res = isrpmvuln(pkg:"grub2-common", rpm:"grub2-common~2.02~73.h20.eulerosv2r9", rls:"EULEROSVIRT-2.9.1"))) {
    report += res;
  }

  if(!isnull(res = isrpmvuln(pkg:"grub2-efi-aa64", rpm:"grub2-efi-aa64~2.02~73.h20.eulerosv2r9", rls:"EULEROSVIRT-2.9.1"))) {
    report += res;
  }

  if(!isnull(res = isrpmvuln(pkg:"grub2-efi-aa64-modules", rpm:"grub2-efi-aa64-modules~2.02~73.h20.eulerosv2r9", rls:"EULEROSVIRT-2.9.1"))) {
    report += res;
  }

  if(!isnull(res = isrpmvuln(pkg:"grub2-tools", rpm:"grub2-tools~2.02~73.h20.eulerosv2r9", rls:"EULEROSVIRT-2.9.1"))) {
    report += res;
  }

  if(report != "") {
    security_message(data:report);
  } else if(__pkg_match) {
    exit(99);
  }
  exit(0);
}

exit(0);