The remote Debian 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-2734 advisory.
curl 7.7 through 7.76.1 suffers from an information disclosure when the -t
command line option, known as CURLOPT_TELNETOPTIONS
in libcurl, is used to send variable=content pairs to TELNET servers. Due to a flaw in the option parser for sending NEW_ENV variables, libcurl could be made to pass on uninitialized data from a stack based buffer to the server, resulting in potentially revealing sensitive internal information to the server using a clear-text network protocol. (CVE-2021-22898)
libcurl keeps previously used connections in a connection pool for subsequenttransfers to reuse, if one of them matches the setup.Due to errors in the logic, the config matching function did not take ‘issuercert’ into account and it compared the involved paths case insensitively,which could lead to libcurl reusing wrong connections.File paths are, or can be, case sensitive on many systems but not all, and caneven vary depending on used file systems.The comparison also didn’t include the ‘issuer cert’ which a transfer can setto qualify how to verify the server certificate. (CVE-2021-22924)
Note that Nessus has not tested for this issue but has instead relied only on the application’s self-reported version number.
#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory dla-2734. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(152547);
script_version("1.4");
script_set_attribute(attribute:"plugin_modification_date", value:"2023/12/04");
script_cve_id("CVE-2021-22898", "CVE-2021-22924");
script_name(english:"Debian DLA-2734-1 : curl - LTS security update");
script_set_attribute(attribute:"synopsis", value:
"The remote Debian host is missing one or more security-related updates.");
script_set_attribute(attribute:"description", value:
"The remote Debian 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the
dla-2734 advisory.
- curl 7.7 through 7.76.1 suffers from an information disclosure when the `-t` command line option, known as
`CURLOPT_TELNETOPTIONS` in libcurl, is used to send variable=content pairs to TELNET servers. Due to a
flaw in the option parser for sending NEW_ENV variables, libcurl could be made to pass on uninitialized
data from a stack based buffer to the server, resulting in potentially revealing sensitive internal
information to the server using a clear-text network protocol. (CVE-2021-22898)
- libcurl keeps previously used connections in a connection pool for subsequenttransfers to reuse, if one of
them matches the setup.Due to errors in the logic, the config matching function did not take 'issuercert'
into account and it compared the involved paths *case insensitively*,which could lead to libcurl reusing
wrong connections.File paths are, or can be, case sensitive on many systems but not all, and caneven vary
depending on used file systems.The comparison also didn't include the 'issuer cert' which a transfer can
setto qualify how to verify the server certificate. (CVE-2021-22924)
Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/source-package/curl");
script_set_attribute(attribute:"see_also", value:"https://www.debian.org/lts/security/2021/dla-2734");
script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2021-22898");
script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2021-22924");
script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/stretch/curl");
script_set_attribute(attribute:"solution", value:
"Upgrade the curl packages.
For Debian 9 stretch, these problems have been fixed in version 7.52.1-5+deb9u15.");
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:H/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-2021-22924");
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:"2021/05/28");
script_set_attribute(attribute:"patch_publication_date", value:"2021/08/13");
script_set_attribute(attribute:"plugin_publication_date", value:"2021/08/13");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:curl");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libcurl3");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libcurl3-dbg");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libcurl3-gnutls");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libcurl3-nss");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libcurl4-doc");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libcurl4-gnutls-dev");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libcurl4-nss-dev");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libcurl4-openssl-dev");
script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:9.0");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Debian 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/Debian/release", "Host/Debian/dpkg-l");
exit(0);
}
include('audit.inc');
include('debian_package.inc');
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);
var release = get_kb_item('Host/Debian/release');
if ( isnull(release) ) audit(AUDIT_OS_NOT, 'Debian');
var release = chomp(release);
if (! preg(pattern:"^(9)\.[0-9]+", string:release)) audit(AUDIT_OS_NOT, 'Debian 9.0', 'Debian ' + release);
var 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, 'Debian', cpu);
var pkgs = [
{'release': '9.0', 'prefix': 'curl', 'reference': '7.52.1-5+deb9u15'},
{'release': '9.0', 'prefix': 'libcurl3', 'reference': '7.52.1-5+deb9u15'},
{'release': '9.0', 'prefix': 'libcurl3-dbg', 'reference': '7.52.1-5+deb9u15'},
{'release': '9.0', 'prefix': 'libcurl3-gnutls', 'reference': '7.52.1-5+deb9u15'},
{'release': '9.0', 'prefix': 'libcurl3-nss', 'reference': '7.52.1-5+deb9u15'},
{'release': '9.0', 'prefix': 'libcurl4-doc', 'reference': '7.52.1-5+deb9u15'},
{'release': '9.0', 'prefix': 'libcurl4-gnutls-dev', 'reference': '7.52.1-5+deb9u15'},
{'release': '9.0', 'prefix': 'libcurl4-nss-dev', 'reference': '7.52.1-5+deb9u15'},
{'release': '9.0', 'prefix': 'libcurl4-openssl-dev', 'reference': '7.52.1-5+deb9u15'}
];
var flag = 0;
foreach package_array ( pkgs ) {
var release = NULL;
var prefix = NULL;
var reference = NULL;
if (!empty_or_null(package_array['release'])) release = package_array['release'];
if (!empty_or_null(package_array['prefix'])) prefix = package_array['prefix'];
if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
if (release && prefix && reference) {
if (deb_check(release:release, prefix:prefix, reference:reference)) flag++;
}
}
if (flag)
{
security_report_v4(
port : 0,
severity : SECURITY_WARNING,
extra : deb_report_get()
);
exit(0);
}
else
{
var tested = deb_pkg_tests_get();
if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'curl / libcurl3 / libcurl3-dbg / libcurl3-gnutls / libcurl3-nss / etc');
}
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-22898
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-22924
packages.debian.org/source/stretch/curl
security-tracker.debian.org/tracker/CVE-2021-22898
security-tracker.debian.org/tracker/CVE-2021-22924
security-tracker.debian.org/tracker/source-package/curl
www.debian.org/lts/security/2021/dla-2734