PKCS#1 Version 1.5 Session Key Retrieval

Medium Nessus Network Monitor Plugin ID 1971


The remote host is vulnerable to a flaw which allows attackers to retrieve sensitive files or data.


The remote host is using version 1.5 of the SSH protocol. This version allows a remote attacker to decrypt and/or alter traffic via an attack against PKCS#1 version 1.5, called the 'Bleichenbacher' attack. OpenSSH up to version 2.3.0, AppGate and SSH Communications Security ssh1 update to version 1.2.31 are vulnerable to this attack.


Upgrade to the latest version of OpenSSH/SSH.

Plugin Details

Severity: Medium

ID: 1971

File Name: 1971.prm

Family: SSH

Published: 2004/08/20

Modified: 2016/02/05

Dependencies: 1967, 3059

Risk Information

Risk Factor: Medium


Base Score: 4

Temporal Score: 3

Vector: CVSS2#AV:N/AC:H/Au:N/C:P/I:P/A:N

Temporal Vector: CVSS2#E:U/RL:OF/RC:C


Base Score: 4.7

Temporal Score: 4.1


Temporal Vector: CVSS3#E:U/RL:O/RC:C

Reference Information

CVE: CVE-2001-0361

BID: 2344