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
98.9%
The version of squid installed on the remote host is prior to 4.15-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2SQUID4-2023-004 advisory.
Squid through 4.14 and 5.x through 5.0.5, in some configurations, allows information disclosure because of an out-of-bounds read in WCCP protocol data. This can be leveraged as part of a chain for remote code execution as nobody. (CVE-2021-28116)
An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a buffer-management bug, it allows a denial of service. When resolving a request with the urn: scheme, the parser leaks a small amount of memory. However, there is an unspecified attack methodology that can easily trigger a large amount of memory consumption. (CVE-2021-28651)
An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to incorrect parser validation, it allows a Denial of Service attack against the Cache Manager API. This allows a trusted client to trigger memory leaks that. over time, lead to a Denial of Service via an unspecified short query string. This attack is limited to clients with Cache Manager API access privilege. (CVE-2021-28652)
An issue was discovered in Squid 4.x before 4.15 and 5.x before 5.0.6. If a remote server sends a certain response header over HTTP or HTTPS, there is a denial of service. This header can plausibly occur in benign network traffic. (CVE-2021-28662)
An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a memory-management bug, it is vulnerable to a Denial of Service attack (against all clients using the proxy) via HTTP Range request processing. (CVE-2021-31806)
An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. An integer overflow problem allows a remote server to achieve Denial of Service when delivering responses to HTTP Range requests. The issue trigger is a header that can be expected to exist in HTTP traffic without any malicious intent.
(CVE-2021-31807)
An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to an input-validation bug, it is vulnerable to a Denial of Service attack (against all clients using the proxy). A client sends an HTTP Range request to trigger this. (CVE-2021-31808)
Squid before 4.15 and 5.x before 5.0.6 allows remote servers to cause a denial of service (affecting availability to all clients) via an HTTP response. The issue trigger is a header that can be expected to exist in HTTP traffic without any malicious intent by the server. (CVE-2021-33620)
Note that Nessus has not tested for these issues but has instead relied only on the application’s self-reported version number.
#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux 2 Security Advisory ALASSQUID4-2023-004.
##
include('compat.inc');
if (description)
{
script_id(181987);
script_version("1.3");
script_set_attribute(attribute:"plugin_modification_date", value:"2023/12/22");
script_cve_id(
"CVE-2021-28116",
"CVE-2021-28651",
"CVE-2021-28652",
"CVE-2021-28662",
"CVE-2021-31806",
"CVE-2021-31807",
"CVE-2021-31808",
"CVE-2021-33620"
);
script_name(english:"Amazon Linux 2 : squid (ALASSQUID4-2023-004)");
script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux 2 host is missing a security update.");
script_set_attribute(attribute:"description", value:
"The version of squid installed on the remote host is prior to 4.15-1. It is, therefore, affected by multiple
vulnerabilities as referenced in the ALAS2SQUID4-2023-004 advisory.
- Squid through 4.14 and 5.x through 5.0.5, in some configurations, allows information disclosure because of
an out-of-bounds read in WCCP protocol data. This can be leveraged as part of a chain for remote code
execution as nobody. (CVE-2021-28116)
- An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a buffer-management bug, it
allows a denial of service. When resolving a request with the urn: scheme, the parser leaks a small amount
of memory. However, there is an unspecified attack methodology that can easily trigger a large amount of
memory consumption. (CVE-2021-28651)
- An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to incorrect parser validation, it
allows a Denial of Service attack against the Cache Manager API. This allows a trusted client to trigger
memory leaks that. over time, lead to a Denial of Service via an unspecified short query string. This
attack is limited to clients with Cache Manager API access privilege. (CVE-2021-28652)
- An issue was discovered in Squid 4.x before 4.15 and 5.x before 5.0.6. If a remote server sends a certain
response header over HTTP or HTTPS, there is a denial of service. This header can plausibly occur in
benign network traffic. (CVE-2021-28662)
- An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a memory-management bug, it is
vulnerable to a Denial of Service attack (against all clients using the proxy) via HTTP Range request
processing. (CVE-2021-31806)
- An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. An integer overflow problem allows a
remote server to achieve Denial of Service when delivering responses to HTTP Range requests. The issue
trigger is a header that can be expected to exist in HTTP traffic without any malicious intent.
(CVE-2021-31807)
- An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to an input-validation bug, it is
vulnerable to a Denial of Service attack (against all clients using the proxy). A client sends an HTTP
Range request to trigger this. (CVE-2021-31808)
- Squid before 4.15 and 5.x before 5.0.6 allows remote servers to cause a denial of service (affecting
availability to all clients) via an HTTP response. The issue trigger is a header that can be expected to
exist in HTTP traffic without any malicious intent by the server. (CVE-2021-33620)
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/AL2/ALASSQUID4-2023-004.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-28116.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-28651.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-28652.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-28662.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-31806.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-31807.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-31808.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2021-33620.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/faqs.html");
script_set_attribute(attribute:"solution", value:
"Run 'yum update squid' to update your system.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:N/A:N");
script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N");
script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-28116");
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:"2021/03/09");
script_set_attribute(attribute:"patch_publication_date", value:"2023/08/21");
script_set_attribute(attribute:"plugin_publication_date", value:"2023/09/27");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:squid");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:squid-debuginfo");
script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Amazon Linux Local Security Checks");
script_copyright(english:"This script is Copyright (C) 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/AmazonLinux/release", "Host/AmazonLinux/rpm-list");
exit(0);
}
include("rpm.inc");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var alas_release = get_kb_item("Host/AmazonLinux/release");
if (isnull(alas_release) || !strlen(alas_release)) audit(AUDIT_OS_NOT, "Amazon Linux");
var os_ver = pregmatch(pattern: "^AL(A|\d+|-\d+)", string:alas_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
os_ver = os_ver[1];
if (os_ver != "2")
{
if (os_ver == 'A') os_ver = 'AMI';
audit(AUDIT_OS_NOT, "Amazon Linux 2", "Amazon Linux " + os_ver);
}
if (!get_kb_item("Host/AmazonLinux/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
var pkgs = [
{'reference':'squid-4.15-1.amzn2.0.1', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'squid4'},
{'reference':'squid-4.15-1.amzn2.0.1', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'squid4'},
{'reference':'squid-4.15-1.amzn2.0.1', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'squid4'},
{'reference':'squid-debuginfo-4.15-1.amzn2.0.1', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'squid4'},
{'reference':'squid-debuginfo-4.15-1.amzn2.0.1', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'squid4'},
{'reference':'squid-debuginfo-4.15-1.amzn2.0.1', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'squid4'}
];
var flag = 0;
foreach var package_array ( pkgs ) {
var reference = NULL;
var _release = NULL;
var sp = NULL;
var _cpu = NULL;
var el_string = NULL;
var rpm_spec_vers_cmp = NULL;
var epoch = NULL;
var allowmaj = NULL;
var exists_check = NULL;
if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
if (!empty_or_null(package_array['release'])) _release = package_array['release'];
if (!empty_or_null(package_array['sp'])) sp = package_array['sp'];
if (!empty_or_null(package_array['cpu'])) _cpu = package_array['cpu'];
if (!empty_or_null(package_array['el_string'])) el_string = package_array['el_string'];
if (!empty_or_null(package_array['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = package_array['rpm_spec_vers_cmp'];
if (!empty_or_null(package_array['epoch'])) epoch = package_array['epoch'];
if (!empty_or_null(package_array['allowmaj'])) allowmaj = package_array['allowmaj'];
if (!empty_or_null(package_array['exists_check'])) exists_check = package_array['exists_check'];
if (reference && _release && (!exists_check || rpm_exists(release:_release, rpm:exists_check))) {
if (rpm_check(release:_release, sp:sp, cpu:_cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj)) flag++;
}
}
if (flag)
{
security_report_v4(
port : 0,
severity : SECURITY_WARNING,
extra : rpm_report_get()
);
exit(0);
}
else
{
var tested = pkg_tests_get();
if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
else audit(AUDIT_PACKAGE_NOT_INSTALLED, "squid / squid-debuginfo");
}
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-28116
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-28651
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-28652
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-28662
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-31806
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-31807
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-31808
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-33620
alas.aws.amazon.com/AL2/ALASSQUID4-2023-004.html
alas.aws.amazon.com/cve/html/CVE-2021-28116.html
alas.aws.amazon.com/cve/html/CVE-2021-28651.html
alas.aws.amazon.com/cve/html/CVE-2021-28652.html
alas.aws.amazon.com/cve/html/CVE-2021-28662.html
alas.aws.amazon.com/cve/html/CVE-2021-31806.html
alas.aws.amazon.com/cve/html/CVE-2021-31807.html
alas.aws.amazon.com/cve/html/CVE-2021-31808.html
alas.aws.amazon.com/cve/html/CVE-2021-33620.html
alas.aws.amazon.com/faqs.html
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
98.9%