CVE-2013-4548: Medium severity openssh vulnerability

Published Nov 8, 2013
·
Updated

The mmnewkeysfromblob function in monitorwrap.c in sshd in OpenSSH 6.2 and 6.3, when an AES-GCM cipher is used, does not properly initialize memory for a MAC context data structure, which allows remote authenticated users to bypass intended ForceCommand and login-shell restrictions via packet data that provides a crafted callback address.

Affected Software

2 affected components
OpenBSD OpenSSH=6.2
OpenBSD OpenSSH=6.3

Event History

Nov 8, 2013
CVE Published
via MITRE·03:00 PM
Data Sourced
via MITRE·03:00 PM
Description

Frequently Asked Questions

1

What is the severity of CVE-2013-4548?

CVE-2013-4548 has a Medium severity rating, allowing certain attacks to bypass command restrictions.

2

How do I fix CVE-2013-4548?

To address CVE-2013-4548, upgrade your OpenSSH version to 6.4 or later, where this vulnerability has been patched.

3

Who is affected by CVE-2013-4548?

CVE-2013-4548 affects users of OpenSSH versions 6.2 and 6.3 running in environments that utilize AES-GCM ciphers.

4

What types of attacks can exploit CVE-2013-4548?

CVE-2013-4548 can be exploited by remote authenticated users to bypass intended ForceCommand and login-shell restrictions.

5

What is the cause of CVE-2013-4548?

CVE-2013-4548 is caused by improper memory initialization for a MAC context data structure within the mm_newkeys_from_blob function.

Contact

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