Red Hat Enterprise Linux 8.6 Extended Update Support update for libssh

Published: 2024-01-29

Risk	High
Patch available	YES
Number of vulnerabilities	3
CVE-ID	CVE-2023-1667 CVE-2023-2283 CVE-2023-48795
CWE-ID	CWE-20 CWE-287 CWE-326
Exploitation vector	Network
Public exploit	N/A
Vulnerable software Subscribe	Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions Operating systems & Components / Operating system package or component libssh (Red Hat package) Operating systems & Components / Operating system package or component Red Hat Enterprise Linux for ARM 64 - Extended Update Support Operating systems & Components / Operating system Red Hat Enterprise Linux Server - TUS Operating systems & Components / Operating system Red Hat Enterprise Linux for Power, little endian - Extended Update Support Operating systems & Components / Operating system Red Hat Enterprise Linux for IBM z Systems - Extended Update Support Operating systems & Components / Operating system Red Hat Enterprise Linux Server - AUS Operating systems & Components / Operating system Red Hat Enterprise Linux for x86_64 - Extended Update Support Operating systems & Components / Operating system
Vendor	Red Hat Inc.

Security Bulletin

This security bulletin contains information about 3 vulnerabilities.

1) Input validation error

EUVDB-ID: #VU75741

Risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2023-1667

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to multiple errors in kex implementation, related to kex guessing algorithm. A remote attacker can bypass implemented security restrictions.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 8.6

Red Hat Enterprise Linux for ARM 64 - Extended Update Support: 8.6

Red Hat Enterprise Linux Server - TUS: 8.6

Red Hat Enterprise Linux for Power, little endian - Extended Update Support: 8.6

Red Hat Enterprise Linux for IBM z Systems - Extended Update Support: 8.6

Red Hat Enterprise Linux Server - AUS: 8.6

Red Hat Enterprise Linux for x86_64 - Extended Update Support: 8.6

libssh (Red Hat package): before 0.9.6-4.el8_6

External links

http://access.redhat.com/errata/RHSA-2024:0538

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Improper Authentication

EUVDB-ID: #VU75740

Risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2023-2283

CWE-ID: CWE-287 - Improper Authentication

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to an error within the pki_verify_data_signature() function in pki_crypto.c. The pki_key_check_hash_compatible() function can return SSH_OK value if memory allocation error happens later in the function. The A remote attacker can bypass authentication process and gain unauthorized access to the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 8.6

Red Hat Enterprise Linux for ARM 64 - Extended Update Support: 8.6

Red Hat Enterprise Linux Server - TUS: 8.6

Red Hat Enterprise Linux for Power, little endian - Extended Update Support: 8.6

Red Hat Enterprise Linux for IBM z Systems - Extended Update Support: 8.6

Red Hat Enterprise Linux Server - AUS: 8.6

Red Hat Enterprise Linux for x86_64 - Extended Update Support: 8.6

libssh (Red Hat package): before 0.9.6-4.el8_6

External links

http://access.redhat.com/errata/RHSA-2024:0538

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

3) Inadequate encryption strength

EUVDB-ID: #VU84537

Risk: Low

CVSSv3.1: 3.2 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2023-48795

CWE-ID: CWE-326 - Inadequate Encryption Strength

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform MitM attack.

The vulnerability exists due to incorrect implementation of the SSH Binary Packet Protocol (BPP), which mishandles the handshake phase and the use of sequence numbers. A remote attacker can perform MitM attack and delete the SSH2_MSG_EXT_INFO message sent before authentication starts, allowing the attacker to disable a subset of the keystroke timing obfuscation features introduced in OpenSSH 9.5.

The vulnerability was dubbed "Terrapin attack" and it affects both client and server implementations.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 8.6

Red Hat Enterprise Linux for ARM 64 - Extended Update Support: 8.6

Red Hat Enterprise Linux Server - TUS: 8.6

Red Hat Enterprise Linux for Power, little endian - Extended Update Support: 8.6

Red Hat Enterprise Linux for IBM z Systems - Extended Update Support: 8.6

Red Hat Enterprise Linux Server - AUS: 8.6

Red Hat Enterprise Linux for x86_64 - Extended Update Support: 8.6

libssh (Red Hat package): before 0.9.6-4.el8_6

External links

http://access.redhat.com/errata/RHSA-2024:0538

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.