CVE-2019-6111

Impact:
Moderate
Public Date:
2018-11-16
CWE:
CWE-20
Bugzilla:
1666127: CVE-2019-6111 openssh: Improper validation of object names allows malicious server to overwrite files via scp client

The MITRE CVE dictionary describes this issue as:

An issue was discovered in OpenSSH 7.9. Due to the scp implementation being derived from 1983 rcp, the server chooses which files/directories are sent to the client. However, the scp client only performs cursory validation of the object name returned (only directory traversal attacks are prevented). A malicious scp server (or Man-in-The-Middle attacker) 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).

Find out more about CVE-2019-6111 from the MITRE CVE dictionary dictionary and NIST NVD.

Statement

This issue affects the scp client shipped with openssh. The SSH protocol or the SSH client is not affected. For more detailed analysis please refer to: https://bugzilla.redhat.com/show_bug.cgi?id=1666127#c2

CVSS v3 metrics

NOTE: The following CVSS v3 metrics and score provided are preliminary and subject to review.

CVSS3 Base Score 5.3
CVSS3 Base Metrics CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N
Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction Required
Scope Unchanged
Confidentiality None
Integrity Impact High
Availability Impact None

Affected Packages State

Platform Package State
Red Hat Enterprise Linux 8 openssh Affected
Red Hat Enterprise Linux 7 openssh Will not fix
Red Hat Enterprise Linux 6 openssh Out of support scope
Red Hat Enterprise Linux 5 openssh Out of support scope

Mitigation

This issue only affects the users of scp binary which is a part of openssh-clients package. Other usage of SSH protocol or other ssh clients is not affected. Administrators can uninstall openssh-clients for additional protection against accidental usage of this binary.

External References

Last Modified

CVE description copyright © 2017, The MITRE Corporation