Denial of service in OpenSSH

1) Null pointer dereference

EUVDB-ID: #VU14163

Risk: Low

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2016-10708

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The vulnerability exists due to improper processing of out-of-sequence NEWKEYS messages, as defined in the kex.c and packet.c source code files. A remote attacker can send an out-of-sequence NEWKEYS message, trigger a NULL pointer dereference condition and cause the sshd daemon to crash.

Mitigation

Update to version 7.4.

Vulnerable software versions

OpenSSH: 6.0p1 - 7.3p1

External links

http://www.openssh.com/releasenotes.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.