EulerOS Virtualization 2.9.0 : libssh (EulerOS-SA-2021-2787)

medium Nessus Plugin ID 155501

Synopsis

The remote EulerOS Virtualization host is missing a security update.

Description

According to the versions of the libssh package installed, the EulerOS Virtualization installation on the remote host is affected by the following vulnerabilities :

- 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)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Solution

Update the affected libssh packages.

See Also

http://www.nessus.org/u?fa9f1f5e

Plugin Details

Severity: Medium

ID: 155501

File Name: EulerOS_SA-2021-2787.nasl

Version: 1.5

Type: local

Published: 11/17/2021

Updated: 10/6/2023

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: Medium

Base Score: 4

Temporal Score: 3

Vector: CVSS2#AV:N/AC:L/Au:S/C:N/I:N/A:P

CVSS Score Source: CVE-2021-3634

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Temporal Score: 5.7

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

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

Vulnerability Information

CPE: p-cpe:/a:huawei:euleros:libssh, cpe:/o:huawei:euleros:uvp:2.9.0

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

Exploit Ease: No known exploits are available

Patch Publication Date: 11/17/2021

Vulnerability Publication Date: 8/31/2021

Reference Information

CVE: CVE-2021-3634

IAVA: 2022-A-0041-S