TencentOS Server 3: libssh (TSSA-2022:0209)

high Nessus Plugin ID 239382

Synopsis

The remote TencentOS Server 3 host is missing one or more security updates.

Description

The version of Tencent Linux installed on the remote TencentOS Server 3 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the TSSA-2022:0209 advisory.

Package updates are available for TencentOS Server 3 that fix the following vulnerabilities:

CVE-2021-3634:
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.

Tenable has extracted the preceding description block directly from the Tencent Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages.

Plugin Details

Severity: High

ID: 239382

File Name: tencentos_TSSA_2022_0209.nasl

Version: 1.1

Type: local

Family: Tencent Local Security Checks

Published: 6/16/2025

Updated: 6/16/2025

Supported Sensors: Nessus

Vulnerability Information

CPE: cpe:/o:tencent:tencentos_server:3, p-cpe:/a:tencent:tencentos_server:libssh

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/etc/os-release, Host/TencentOS/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 12/2/2022

Vulnerability Publication Date: 12/2/2022

Detections

Analytics