CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AI Score
Confidence
High
EPSS
Percentile
89.0%
According to the versions of the unbound package installed, the EulerOS Virtualization installation on the remote host is affected by the following vulnerabilities :
NLnet Labs Unbound, up to and including version 1.12.0, and NLnet Labs NSD, up to and including version 4.3.3, contain a local vulnerability that would allow for a local symlink attack. When writing the PID file, Unbound and NSD create the file if it is not there, or open an existing file for writing. In case the file was already present, they would follow symlinks if the file happened to be a symlink instead of a regular file. An additional chown of the file would then take place after it was written, making the user Unbound/NSD is supposed to run as the new owner of the file. If an attacker has local access to the user Unbound/NSD runs as, she could create a symlink in place of the PID file pointing to a file that she would like to erase. If then Unbound/NSD is killed and the PID file is not cleared, upon restarting with root privileges, Unbound/NSD will rewrite any file pointed at by the symlink. This is a local vulnerability that could create a Denial of Service of the system Unbound/NSD is running on. It requires an attacker having access to the limited permission user Unbound/NSD runs as and point through the symlink to a critical file on the system.(CVE-2020-28935)
Unbound before 1.10.1 has Insufficient Control of Network Message Volume, aka an ‘NXNSAttack’ issue. This is triggered by random subdomains in the NSDNAME in NS records.(CVE-2020-12662)
Unbound before 1.10.1 has an infinite loop via malformed DNS answers received from upstream servers.(CVE-2020-12663)
Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(151378);
script_version("1.3");
script_set_attribute(attribute:"plugin_modification_date", value:"2023/12/11");
script_cve_id("CVE-2020-12662", "CVE-2020-12663", "CVE-2020-28935");
script_name(english:"EulerOS Virtualization 3.0.2.2 : unbound (EulerOS-SA-2021-2172)");
script_set_attribute(attribute:"synopsis", value:
"The remote EulerOS Virtualization host is missing multiple security
updates.");
script_set_attribute(attribute:"description", value:
"According to the versions of the unbound package installed, the
EulerOS Virtualization installation on the remote host is affected by
the following vulnerabilities :
- NLnet Labs Unbound, up to and including version 1.12.0,
and NLnet Labs NSD, up to and including version 4.3.3,
contain a local vulnerability that would allow for a
local symlink attack. When writing the PID file,
Unbound and NSD create the file if it is not there, or
open an existing file for writing. In case the file was
already present, they would follow symlinks if the file
happened to be a symlink instead of a regular file. An
additional chown of the file would then take place
after it was written, making the user Unbound/NSD is
supposed to run as the new owner of the file. If an
attacker has local access to the user Unbound/NSD runs
as, she could create a symlink in place of the PID file
pointing to a file that she would like to erase. If
then Unbound/NSD is killed and the PID file is not
cleared, upon restarting with root privileges,
Unbound/NSD will rewrite any file pointed at by the
symlink. This is a local vulnerability that could
create a Denial of Service of the system Unbound/NSD is
running on. It requires an attacker having access to
the limited permission user Unbound/NSD runs as and
point through the symlink to a critical file on the
system.(CVE-2020-28935)
- Unbound before 1.10.1 has Insufficient Control of
Network Message Volume, aka an 'NXNSAttack' issue. This
is triggered by random subdomains in the NSDNAME in NS
records.(CVE-2020-12662)
- Unbound before 1.10.1 has an infinite loop via
malformed DNS answers received from upstream
servers.(CVE-2020-12663)
Note that Tenable Network Security has extracted the preceding
description block directly from the EulerOS security advisory. Tenable
has attempted to automatically clean and format it as much as possible
without introducing additional issues.");
# https://developer.huaweicloud.com/ict/en/site-euleros/euleros/security-advisories/EulerOS-SA-2021-2172
script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?7bb71aaf");
script_set_attribute(attribute:"solution", value:
"Update the affected unbound packages.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
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:N/A:H");
script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-12663");
script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
script_set_attribute(attribute:"exploit_available", value:"false");
script_set_attribute(attribute:"patch_publication_date", value:"2021/07/06");
script_set_attribute(attribute:"plugin_publication_date", value:"2021/07/06");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:unbound-libs");
script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:uvp:3.0.2.2");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Huawei Local Security Checks");
script_copyright(english:"This script is Copyright (C) 2021-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("ssh_get_info.nasl");
script_require_keys("Host/local_checks_enabled", "Host/cpu", "Host/EulerOS/release", "Host/EulerOS/rpm-list", "Host/EulerOS/uvp_version");
exit(0);
}
include("audit.inc");
include("global_settings.inc");
include("rpm.inc");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/EulerOS/release");
if (isnull(release) || release !~ "^EulerOS") audit(AUDIT_OS_NOT, "EulerOS");
uvp = get_kb_item("Host/EulerOS/uvp_version");
if (uvp != "3.0.2.2") audit(AUDIT_OS_NOT, "EulerOS Virtualization 3.0.2.2");
if (!get_kb_item("Host/EulerOS/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "aarch64" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "EulerOS", cpu);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_ARCH_NOT, "i686 / x86_64", cpu);
flag = 0;
pkgs = ["unbound-libs-1.6.6-1.h4.eulerosv2r7"];
foreach (pkg in pkgs)
if (rpm_check(release:"EulerOS-2.0", reference:pkg)) flag++;
if (flag)
{
security_report_v4(
port : 0,
severity : SECURITY_WARNING,
extra : rpm_report_get()
);
exit(0);
}
else
{
tested = pkg_tests_get();
if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
else audit(AUDIT_PACKAGE_NOT_INSTALLED, "unbound");
}
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AI Score
Confidence
High
EPSS
Percentile
89.0%