The version of libssh installed on the remote host is prior to 0.10.5. It is, therefore, affected by multiple vulnerabilities as referenced in the SSA:2023-124-01 advisory.
A vulnerability was found in libssh, where the authentication check of the connecting client can be bypassed in thepki_verify_data_signature
function in memory allocation problems. This issue may happen if there is insufficient memory or the memory usage is limited. The problem is caused by the return value rc,
which is initialized to SSH_ERROR and later rewritten to save the return value of the function call pki_key_check_hash_compatible.
The value of the variable is not changed between this point and the cryptographic verification. Therefore any error between them calls goto error
returning SSH_OK.
(CVE-2023-2283)
A NULL pointer dereference was found In libssh during re-keying with algorithm guessing. This issue may allow an authenticated client to cause a denial of service. (CVE-2023-1667)
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 Slackware Security Advisory SSA:2023-124-01. The text
# itself is copyright (C) Slackware Linux, Inc.
##
include('compat.inc');
if (description)
{
script_id(175121);
script_version("1.5");
script_set_attribute(attribute:"plugin_modification_date", value:"2023/12/22");
script_cve_id("CVE-2023-1667", "CVE-2023-2283");
script_xref(name:"IAVA", value:"2023-A-0517-S");
script_name(english:"Slackware Linux 14.2 / 15.0 / current libssh Multiple Vulnerabilities (SSA:2023-124-01)");
script_set_attribute(attribute:"synopsis", value:
"The remote Slackware Linux host is missing a security update to libssh.");
script_set_attribute(attribute:"description", value:
"The version of libssh installed on the remote host is prior to 0.10.5. It is, therefore, affected by multiple
vulnerabilities as referenced in the SSA:2023-124-01 advisory.
- A vulnerability was found in libssh, where the authentication check of the connecting client can be
bypassed in the`pki_verify_data_signature` function in memory allocation problems. This issue may happen
if there is insufficient memory or the memory usage is limited. The problem is caused by the return value
`rc,` which is initialized to SSH_ERROR and later rewritten to save the return value of the function call
`pki_key_check_hash_compatible.` The value of the variable is not changed between this point and the
cryptographic verification. Therefore any error between them calls `goto error` returning SSH_OK.
(CVE-2023-2283)
- A NULL pointer dereference was found In libssh during re-keying with algorithm guessing. This issue may
allow an authenticated client to cause a denial of service. (CVE-2023-1667)
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:"solution", value:
"Upgrade the affected libssh package.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/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:L/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-2023-2283");
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:"2023/05/04");
script_set_attribute(attribute:"patch_publication_date", value:"2023/05/04");
script_set_attribute(attribute:"plugin_publication_date", value:"2023/05/04");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:slackware:slackware_linux:libssh");
script_set_attribute(attribute:"cpe", value:"cpe:/o:slackware:slackware_linux");
script_set_attribute(attribute:"cpe", value:"cpe:/o:slackware:slackware_linux:14.2");
script_set_attribute(attribute:"cpe", value:"cpe:/o:slackware:slackware_linux:15.0");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_set_attribute(attribute:"stig_severity", value:"II");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Slackware 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/Slackware/release", "Host/Slackware/packages");
exit(0);
}
include("slackware.inc");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Slackware/release")) audit(AUDIT_OS_NOT, "Slackware");
if (!get_kb_item("Host/Slackware/packages")) 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$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Slackware", cpu);
var flag = 0;
var constraints = [
{ 'fixed_version' : '0.10.5', 'product' : 'libssh', 'os_name' : 'Slackware Linux', 'os_version' : '14.2', 'service_pack' : '1_slack14.2', 'arch' : 'i586' },
{ 'fixed_version' : '0.10.5', 'product' : 'libssh', 'os_name' : 'Slackware Linux', 'os_version' : '14.2', 'service_pack' : '1_slack14.2', 'arch' : 'x86_64' },
{ 'fixed_version' : '0.10.5', 'product' : 'libssh', 'os_name' : 'Slackware Linux', 'os_version' : '15.0', 'service_pack' : '1_slack15.0', 'arch' : 'i586' },
{ 'fixed_version' : '0.10.5', 'product' : 'libssh', 'os_name' : 'Slackware Linux', 'os_version' : '15.0', 'service_pack' : '1_slack15.0', 'arch' : 'x86_64' },
{ 'fixed_version' : '0.10.5', 'product' : 'libssh', 'os_name' : 'Slackware Linux', 'os_version' : 'current', 'service_pack' : '1', 'arch' : 'i586' },
{ 'fixed_version' : '0.10.5', 'product' : 'libssh', 'os_name' : 'Slackware Linux', 'os_version' : 'current', 'service_pack' : '1', 'arch' : 'x86_64' }
];
foreach constraint (constraints) {
var pkg_arch = constraint['arch'];
var arch = NULL;
if (pkg_arch == "x86_64") {
arch = pkg_arch;
}
if (slackware_check(osver:constraint['os_version'],
arch:arch,
pkgname:constraint['product'],
pkgver:constraint['fixed_version'],
pkgarch:pkg_arch,
pkgnum:constraint['service_pack'])) flag++;
}
if (flag)
{
security_report_v4(
port : 0,
severity : SECURITY_WARNING,
extra : slackware_report_get()
);
exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");
Vendor | Product | Version | CPE |
---|---|---|---|
slackware | slackware_linux | libssh | p-cpe:/a:slackware:slackware_linux:libssh |
slackware | slackware_linux | cpe:/o:slackware:slackware_linux | |
slackware | slackware_linux | 14.2 | cpe:/o:slackware:slackware_linux:14.2 |
slackware | slackware_linux | 15.0 | cpe:/o:slackware:slackware_linux:15.0 |