OpenSSH < 8.0 Multiple Vulnerbilities

2019-08-2100:00:00

Tenable

www.tenable.com

CVSS2

5.8

Attack Vector

NETWORK

Attack Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

NONE

Integrity Impact

PARTIAL

Availability Impact

PARTIAL

AV:N/AC:M/Au:N/C:N/I:P/A:P

CVSS3

6.8

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

NONE

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

EPSS

0.004

Percentile

74.5%

The installed version of OpenSSH is prior to 8.0 and is affected by multiple vulnerabilities:

The scp client allows remote SSH servers to bypass intended access restrictions via the filename of ‘.’’ or an empty filename. The impact is modifying the permissions of the target directory on the client side. (CVE-2018-20685)
Due to missing character encoding in the progress display, a malicious server can employ crafted object names to manipulate the client output, e.g., by using ANSI control codes to hide additional files being transferred. This affects ‘refresh_progress_meter()’ in progressmeter.c. (CVE-2019-6109)
Due to accepting and displaying arbitrary stderr output from the server, a malicious server can manipulate the client output, for example to use ANSI control codes to hide additional files being transferred. (CVE-2019-6110)
A malicious scp server can overwrite arbitrary files in the scp client target directory. If recursive operation (-r) is performed, the server can manipulate subdirectories as well (for example, to overwrite the .ssh/authorized_keys file). (CVE-2019-6111)