SUSE SLES15 Security Update : libssh (SUSE-SU-2024:0525-1)

high Nessus Plugin ID 190754

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Synopsis

The remote SUSE host is missing one or more security updates.

Description

The remote SUSE Linux SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2024:0525-1 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.

Solution

Update the affected libssh-config, libssh-devel, libssh4 and / or libssh4-32bit packages.

See Also

https://bugzilla.suse.com/1158095

https://bugzilla.suse.com/1168699

https://bugzilla.suse.com/1174713

https://bugzilla.suse.com/1189608

https://bugzilla.suse.com/1211188

https://bugzilla.suse.com/1211190

https://bugzilla.suse.com/1218126

https://bugzilla.suse.com/1218186

https://bugzilla.suse.com/1218209

http://www.nessus.org/u?dfde76e2

https://www.suse.com/security/cve/CVE-2019-14889

https://www.suse.com/security/cve/CVE-2020-16135

https://www.suse.com/security/cve/CVE-2020-1730

https://www.suse.com/security/cve/CVE-2021-3634

https://www.suse.com/security/cve/CVE-2023-1667

https://www.suse.com/security/cve/CVE-2023-2283

https://www.suse.com/security/cve/CVE-2023-48795

https://www.suse.com/security/cve/CVE-2023-6004

https://www.suse.com/security/cve/CVE-2023-6918

Plugin Details

Severity: High

ID: 190754

File Name: suse_SU-2024-0525-1.nasl

Version: 1.0

Type: local

Agent: unix

Published: 2/20/2024

Updated: 2/20/2024

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: High

Base Score: 9.3

Temporal Score: 7.3

Vector: CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2019-14889

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.9

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:novell:suse_linux:libssh-config, p-cpe:/a:novell:suse_linux:libssh-devel, p-cpe:/a:novell:suse_linux:libssh4, p-cpe:/a:novell:suse_linux:libssh4-32bit, cpe:/o:novell:suse_linux:15

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/SuSE/release, Host/SuSE/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 2/19/2024

Vulnerability Publication Date: 12/10/2019

Reference Information

CVE: CVE-2019-14889, CVE-2020-16135, CVE-2020-1730, CVE-2021-3634, CVE-2023-1667, CVE-2023-2283, CVE-2023-48795, CVE-2023-6004, CVE-2023-6918

IAVA: 2020-A-0203, 2022-A-0041-S, 2023-A-0517-S, 2023-A-0703

SuSE: SUSE-SU-2024:0525-1