CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:M/Au:N/C:C/I:C/A:C
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
AI Score
Confidence
Low
EPSS
Percentile
99.6%
The remote SUSE Linux SLES12 / SLES_SAP12 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2024:0539-1 advisory.
A flaw was found with the libssh API function ssh_scp_new() in versions before 0.9.3 and before 0.8.8.
When the libssh SCP client connects to a server, the scp command, which includes a user-provided path, is executed on the server-side. In case the library is used in a way where users can influence the third parameter of the function, it would become possible for an attacker to inject arbitrary commands, leading to a compromise of the remote target. (CVE-2019-14889)
libssh 0.9.4 has a NULL pointer dereference in tftpserver.c if ssh_buffer_new returns NULL.
(CVE-2020-16135)
A flaw was found in libssh versions before 0.8.9 and before 0.9.4 in the way it handled AES-CTR (or DES ciphers if enabled) ciphers. The server or client could crash when the connection hasn’t been fully initialized and the system tries to cleanup the ciphers when closing the connection. The biggest threat from this vulnerability is system availability. (CVE-2020-1730)
A flaw has been found in libssh in versions prior to 0.9.6. The SSH protocol keeps track of two shared secrets during the lifetime of the session. One of them is called secret_hash and the other session_id.
Initially, both of them are the same, but after key re-exchange, previous session_id is kept and used as an input to new secret_hash. Historically, both of these buffers had shared length variable, which worked as long as these buffers were same. But the key re-exchange operation can also change the key exchange method, which can be based on hash of different size, eventually creating secret_hash of different size than the session_id has. This becomes an issue when the session_id memory is zeroed or when it is used again during second key re-exchange. (CVE-2021-3634)
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)
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)
The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the extension negotiation message), and a client and server may consequently end up with a connection for which some security features have been downgraded or disabled, aka a Terrapin attack. This occurs because the SSH Binary Packet Protocol (BPP), implemented by these extensions, mishandles the handshake phase and mishandles use of sequence numbers. For example, there is an effective attack against SSH’s use of ChaCha20-Poly1305 (and CBC with Encrypt-then-MAC). The bypass occurs in [email protected] and (if CBC is used) the [email protected] MAC algorithms. This also affects Maverick Synergy Java SSH API before 3.1.0-SNAPSHOT, Dropbear through 2022.83, Ssh before 5.1.1 in Erlang/OTP, PuTTY before 0.80, AsyncSSH before 2.14.2, golang.org/x/crypto before 0.17.0, libssh before 0.10.6, libssh2 through 1.11.0, Thorn Tech SFTP Gateway before 3.4.6, Tera Term before 5.1, Paramiko before 3.4.0, jsch before 0.2.15, SFTPGo before 2.5.6, Netgate pfSense Plus through 23.09.1, Netgate pfSense CE through 2.7.2, HPN-SSH through 18.2.0, ProFTPD before 1.3.8b (and before 1.3.9rc2), ORYX CycloneSSH before 2.3.4, NetSarang XShell 7 before Build 0144, CrushFTP before 10.6.0, ConnectBot SSH library before 2.2.22, Apache MINA sshd through 2.11.0, sshj through 0.37.0, TinySSH through 20230101, trilead-ssh2 6401, LANCOM LCOS and LANconfig, FileZilla before 3.66.4, Nova before 11.8, PKIX-SSH before 14.4, SecureCRT before 9.4.3, Transmit5 before 5.10.4, Win32-OpenSSH before 9.5.0.0p1-Beta, WinSCP before 6.2.2, Bitvise SSH Server before 9.32, Bitvise SSH Client before 9.33, KiTTY through 0.76.1.13, the net-ssh gem 7.2.0 for Ruby, the mscdex ssh2 module before 1.15.0 for Node.js, the thrussh library before 0.35.1 for Rust, and the Russh crate before 0.40.2 for Rust. (CVE-2023-48795)
A flaw was found in libssh. By utilizing the ProxyCommand or ProxyJump feature, users can exploit unchecked hostname syntax on the client. This issue may allow an attacker to inject malicious code into the command of the features mentioned through the hostname parameter. (CVE-2023-6004)
A flaw was found in the libssh implements abstract layer for message digest (MD) operations implemented by different supported crypto backends. The return values from these were not properly checked, which could cause low-memory situations failures, NULL dereferences, crashes, or usage of the uninitialized memory as an input for the KDF. In this case, non-matching keys will result in decryption/integrity failures, terminating the connection. (CVE-2023-6918)
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 package checks in this plugin were extracted from
# SUSE update advisory SUSE-SU-2024:0539-1. The text itself
# is copyright (C) SUSE.
##
include('compat.inc');
if (description)
{
script_id(190835);
script_version("1.0");
script_set_attribute(attribute:"plugin_modification_date", value:"2024/02/21");
script_cve_id(
"CVE-2019-14889",
"CVE-2020-1730",
"CVE-2020-16135",
"CVE-2021-3634",
"CVE-2023-1667",
"CVE-2023-2283",
"CVE-2023-6004",
"CVE-2023-6918",
"CVE-2023-48795"
);
script_xref(name:"IAVA", value:"2020-A-0203");
script_xref(name:"IAVA", value:"2022-A-0041-S");
script_xref(name:"IAVA", value:"2023-A-0517-S");
script_xref(name:"IAVA", value:"2023-A-0703");
script_xref(name:"SuSE", value:"SUSE-SU-2024:0539-1");
script_name(english:"SUSE SLES12 Security Update : libssh (SUSE-SU-2024:0539-1)");
script_set_attribute(attribute:"synopsis", value:
"The remote SUSE host is missing one or more security updates.");
script_set_attribute(attribute:"description", value:
"The remote SUSE Linux SLES12 / SLES_SAP12 host has packages installed that are affected by multiple vulnerabilities as
referenced in the SUSE-SU-2024:0539-1 advisory.
- A flaw was found with the libssh API function ssh_scp_new() in versions before 0.9.3 and before 0.8.8.
When the libssh SCP client connects to a server, the scp command, which includes a user-provided path, is
executed on the server-side. In case the library is used in a way where users can influence the third
parameter of the function, it would become possible for an attacker to inject arbitrary commands, leading
to a compromise of the remote target. (CVE-2019-14889)
- libssh 0.9.4 has a NULL pointer dereference in tftpserver.c if ssh_buffer_new returns NULL.
(CVE-2020-16135)
- A flaw was found in libssh versions before 0.8.9 and before 0.9.4 in the way it handled AES-CTR (or DES
ciphers if enabled) ciphers. The server or client could crash when the connection hasn't been fully
initialized and the system tries to cleanup the ciphers when closing the connection. The biggest threat
from this vulnerability is system availability. (CVE-2020-1730)
- A flaw has been found in libssh in versions prior to 0.9.6. The SSH protocol keeps track of two shared
secrets during the lifetime of the session. One of them is called secret_hash and the other session_id.
Initially, both of them are the same, but after key re-exchange, previous session_id is kept and used as
an input to new secret_hash. Historically, both of these buffers had shared length variable, which worked
as long as these buffers were same. But the key re-exchange operation can also change the key exchange
method, which can be based on hash of different size, eventually creating secret_hash of different size
than the session_id has. This becomes an issue when the session_id memory is zeroed or when it is used
again during second key re-exchange. (CVE-2021-3634)
- 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)
- 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)
- The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other
products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the
extension negotiation message), and a client and server may consequently end up with a connection for
which some security features have been downgraded or disabled, aka a Terrapin attack. This occurs because
the SSH Binary Packet Protocol (BPP), implemented by these extensions, mishandles the handshake phase and
mishandles use of sequence numbers. For example, there is an effective attack against SSH's use of
ChaCha20-Poly1305 (and CBC with Encrypt-then-MAC). The bypass occurs in [email protected] and
(if CBC is used) the [email protected] MAC algorithms. This also affects Maverick Synergy Java SSH API
before 3.1.0-SNAPSHOT, Dropbear through 2022.83, Ssh before 5.1.1 in Erlang/OTP, PuTTY before 0.80,
AsyncSSH before 2.14.2, golang.org/x/crypto before 0.17.0, libssh before 0.10.6, libssh2 through 1.11.0,
Thorn Tech SFTP Gateway before 3.4.6, Tera Term before 5.1, Paramiko before 3.4.0, jsch before 0.2.15,
SFTPGo before 2.5.6, Netgate pfSense Plus through 23.09.1, Netgate pfSense CE through 2.7.2, HPN-SSH
through 18.2.0, ProFTPD before 1.3.8b (and before 1.3.9rc2), ORYX CycloneSSH before 2.3.4, NetSarang
XShell 7 before Build 0144, CrushFTP before 10.6.0, ConnectBot SSH library before 2.2.22, Apache MINA sshd
through 2.11.0, sshj through 0.37.0, TinySSH through 20230101, trilead-ssh2 6401, LANCOM LCOS and
LANconfig, FileZilla before 3.66.4, Nova before 11.8, PKIX-SSH before 14.4, SecureCRT before 9.4.3,
Transmit5 before 5.10.4, Win32-OpenSSH before 9.5.0.0p1-Beta, WinSCP before 6.2.2, Bitvise SSH Server
before 9.32, Bitvise SSH Client before 9.33, KiTTY through 0.76.1.13, the net-ssh gem 7.2.0 for Ruby, the
mscdex ssh2 module before 1.15.0 for Node.js, the thrussh library before 0.35.1 for Rust, and the Russh
crate before 0.40.2 for Rust. (CVE-2023-48795)
- A flaw was found in libssh. By utilizing the ProxyCommand or ProxyJump feature, users can exploit
unchecked hostname syntax on the client. This issue may allow an attacker to inject malicious code into
the command of the features mentioned through the hostname parameter. (CVE-2023-6004)
- A flaw was found in the libssh implements abstract layer for message digest (MD) operations implemented by
different supported crypto backends. The return values from these were not properly checked, which could
cause low-memory situations failures, NULL dereferences, crashes, or usage of the uninitialized memory as
an input for the KDF. In this case, non-matching keys will result in decryption/integrity failures,
terminating the connection. (CVE-2023-6918)
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://bugzilla.suse.com/1158095");
script_set_attribute(attribute:"see_also", value:"https://bugzilla.suse.com/1168699");
script_set_attribute(attribute:"see_also", value:"https://bugzilla.suse.com/1174713");
script_set_attribute(attribute:"see_also", value:"https://bugzilla.suse.com/1189608");
script_set_attribute(attribute:"see_also", value:"https://bugzilla.suse.com/1211188");
script_set_attribute(attribute:"see_also", value:"https://bugzilla.suse.com/1211190");
script_set_attribute(attribute:"see_also", value:"https://bugzilla.suse.com/1218126");
script_set_attribute(attribute:"see_also", value:"https://bugzilla.suse.com/1218186");
script_set_attribute(attribute:"see_also", value:"https://bugzilla.suse.com/1218209");
# https://lists.suse.com/pipermail/sle-security-updates/2024-February/017974.html
script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?32db50ee");
script_set_attribute(attribute:"see_also", value:"https://www.suse.com/security/cve/CVE-2019-14889");
script_set_attribute(attribute:"see_also", value:"https://www.suse.com/security/cve/CVE-2020-16135");
script_set_attribute(attribute:"see_also", value:"https://www.suse.com/security/cve/CVE-2020-1730");
script_set_attribute(attribute:"see_also", value:"https://www.suse.com/security/cve/CVE-2021-3634");
script_set_attribute(attribute:"see_also", value:"https://www.suse.com/security/cve/CVE-2023-1667");
script_set_attribute(attribute:"see_also", value:"https://www.suse.com/security/cve/CVE-2023-2283");
script_set_attribute(attribute:"see_also", value:"https://www.suse.com/security/cve/CVE-2023-48795");
script_set_attribute(attribute:"see_also", value:"https://www.suse.com/security/cve/CVE-2023-6004");
script_set_attribute(attribute:"see_also", value:"https://www.suse.com/security/cve/CVE-2023-6918");
script_set_attribute(attribute:"solution", value:
"Update the affected libssh-config, libssh-devel, libssh4 and / or libssh4-32bit packages.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:C");
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:R/S:U/C:H/I:H/A:H");
script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2019-14889");
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:"2019/12/10");
script_set_attribute(attribute:"patch_publication_date", value:"2024/02/20");
script_set_attribute(attribute:"plugin_publication_date", value:"2024/02/21");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:libssh-config");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:libssh-devel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:libssh4");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:libssh4-32bit");
script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:suse_linux:12");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_set_attribute(attribute:"stig_severity", value:"I");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"SuSE Local Security Checks");
script_copyright(english:"This script is Copyright (C) 2024 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/SuSE/release", "Host/SuSE/rpm-list");
exit(0);
}
include('rpm.inc');
if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item("Host/SuSE/release");
if (isnull(os_release) || os_release !~ "^(SLED|SLES)") audit(AUDIT_OS_NOT, "SUSE");
var os_ver = pregmatch(pattern: "^(SLE(S|D)(?:_SAP)?\d+)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'SUSE');
os_ver = os_ver[1];
if (! preg(pattern:"^(SLES12|SLES_SAP12)$", string:os_ver)) audit(AUDIT_OS_NOT, 'SUSE SLES12 / SLES_SAP12', 'SUSE (' + os_ver + ')');
if (!get_kb_item("Host/SuSE/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'SUSE (' + os_ver + ')', cpu);
var service_pack = get_kb_item("Host/SuSE/patchlevel");
if (isnull(service_pack)) service_pack = "0";
if (os_ver == "SLES12" && (! preg(pattern:"^(5)$", string:service_pack))) audit(AUDIT_OS_NOT, "SLES12 SP5", os_ver + " SP" + service_pack);
if (os_ver == "SLES_SAP12" && (! preg(pattern:"^(5)$", string:service_pack))) audit(AUDIT_OS_NOT, "SLES_SAP12 SP5", os_ver + " SP" + service_pack);
var pkgs = [
{'reference':'libssh-config-0.9.8-3.12.2', 'sp':'5', 'release':'SLES_SAP12', 'rpm_spec_vers_cmp':TRUE, 'exists_check':['SLES_SAP-release-12.5']},
{'reference':'libssh-devel-0.9.8-3.12.2', 'sp':'5', 'release':'SLES_SAP12', 'rpm_spec_vers_cmp':TRUE, 'exists_check':['SLES_SAP-release-12.5']},
{'reference':'libssh4-0.9.8-3.12.2', 'sp':'5', 'release':'SLES_SAP12', 'rpm_spec_vers_cmp':TRUE, 'exists_check':['SLES_SAP-release-12.5']},
{'reference':'libssh4-32bit-0.9.8-3.12.2', 'sp':'5', 'release':'SLES_SAP12', 'rpm_spec_vers_cmp':TRUE, 'exists_check':['SLES_SAP-release-12.5']},
{'reference':'libssh-devel-0.9.8-3.12.2', 'sp':'5', 'release':'SLES12', 'rpm_spec_vers_cmp':TRUE, 'exists_check':['sle-sdk-release-12.5', 'sles-release-12.5']},
{'reference':'libssh4-0.9.8-3.12.2', 'sp':'5', 'release':'SLES12', 'rpm_spec_vers_cmp':TRUE, 'exists_check':['sle-sdk-release-12.5', 'sles-release-12.5']},
{'reference':'libssh-config-0.9.8-3.12.2', 'sp':'5', 'release':'SLES12', 'rpm_spec_vers_cmp':TRUE, 'exists_check':['sles-release-12.5']},
{'reference':'libssh4-32bit-0.9.8-3.12.2', 'sp':'5', 'release':'SLES12', 'rpm_spec_vers_cmp':TRUE, 'exists_check':['sles-release-12.5']}
];
var ltss_caveat_required = FALSE;
var flag = 0;
foreach var package_array ( pkgs ) {
var reference = NULL;
var _release = NULL;
var sp = NULL;
var _cpu = NULL;
var exists_check = NULL;
var rpm_spec_vers_cmp = 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['exists_check'])) exists_check = package_array['exists_check'];
if (!empty_or_null(package_array['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = package_array['rpm_spec_vers_cmp'];
if (reference && _release) {
if (exists_check) {
var check_flag = 0;
foreach var check (exists_check) {
if (!rpm_exists(release:_release, rpm:check)) continue;
check_flag++;
}
if (!check_flag) continue;
}
if (rpm_check(release:_release, sp:sp, cpu:_cpu, reference:reference, rpm_spec_vers_cmp:rpm_spec_vers_cmp)) flag++;
}
}
if (flag)
{
security_report_v4(
port : 0,
severity : SECURITY_HOLE,
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, 'libssh-config / libssh-devel / libssh4 / libssh4-32bit');
}
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-14889
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-16135
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-1730
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3634
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-1667
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-2283
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-48795
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-6004
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-6918
www.nessus.org/u?32db50ee
bugzilla.suse.com/1158095
bugzilla.suse.com/1168699
bugzilla.suse.com/1174713
bugzilla.suse.com/1189608
bugzilla.suse.com/1211188
bugzilla.suse.com/1211190
bugzilla.suse.com/1218126
bugzilla.suse.com/1218186
bugzilla.suse.com/1218209
www.suse.com/security/cve/CVE-2019-14889
www.suse.com/security/cve/CVE-2020-16135
www.suse.com/security/cve/CVE-2020-1730
www.suse.com/security/cve/CVE-2021-3634
www.suse.com/security/cve/CVE-2023-1667
www.suse.com/security/cve/CVE-2023-2283
www.suse.com/security/cve/CVE-2023-48795
www.suse.com/security/cve/CVE-2023-6004
www.suse.com/security/cve/CVE-2023-6918
CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:M/Au:N/C:C/I:C/A:C
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
AI Score
Confidence
Low
EPSS
Percentile
99.6%