Your submission was sent successfully! Close

You have successfully unsubscribed! Close

Thank you for signing up for our newsletter!
In these regular emails you will find the latest updates about Ubuntu and upcoming events where you can meet our team.Close

CVE-2018-20685

Published: 10 January 2019

In OpenSSH 7.9, scp.c in 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.

Notes

AuthorNote
seth-arnold
openssh-ssh1 is provided for compatibility with old devices that
cannot be upgraded to modern protocols. Thus we may not provide security
support for this package if doing so would prevent access to equipment.
mdeslaur
The recommended workaround for this issue is to switch to using
sftp instead of scp.

Priority

Medium

Cvss 3 Severity Score

5.3

Score breakdown

Status

Package Release Status
openssh-ssh1
Launchpad, Ubuntu, Debian
groovy Ignored
(end of life)
hirsute Ignored
(end of life)
jammy Needs triage

impish Ignored
(end of life)
kinetic Ignored
(end of life, was needs-triage)
bionic Needs triage

cosmic Ignored
(end of life)
disco Ignored
(end of life)
eoan Ignored
(end of life)
focal Needs triage

trusty Does not exist

upstream Ignored
(frozen on openssh 7.5p)
xenial Does not exist

mantic Needs triage

lunar Ignored
(end of life, was needs-triage)
openssh
Launchpad, Ubuntu, Debian
hirsute
Released (1:7.9p1-5)
jammy
Released (1:7.9p1-5)
kinetic
Released (1:7.9p1-5)
bionic
Released (1:7.6p1-4ubuntu0.2)
cosmic
Released (1:7.7p1-4ubuntu0.2)
disco
Released (1:7.9p1-5)
eoan
Released (1:7.9p1-5)
focal
Released (1:7.9p1-5)
groovy
Released (1:7.9p1-5)
impish
Released (1:7.9p1-5)
lunar
Released (1:7.9p1-5)
trusty
Released (1:6.6p1-2ubuntu2.12)
upstream
Released (1:7.9p1-5)
xenial
Released (1:7.2p2-4ubuntu2.7)
mantic
Released (1:7.9p1-5)
Patches:
upstream: https://github.com/openssh/openssh-portable/commit/6010c0303a422a9c5fa8860c061bf7105eb7f8b2
upstream: https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/scp.c.diff?r1=1.197&r2=1.198&f=h

Severity score breakdown

Parameter Value
Base score 5.3
Attack vector Network
Attack complexity High
Privileges required None
User interaction Required
Scope Unchanged
Confidentiality None
Integrity impact High
Availability impact None
Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N