The version of OpenSSH installed on the remote host is prior to 9.8. It is, therefore, affected by a vulnerability as referenced in the release-9.8 advisory.

  - This release contains fixes for two security problems, one critical and one minor. 1) Race condition in     sshd(8) A critical vulnerability in sshd(8) was present in Portable OpenSSH versions between 8.5p1 and     9.7p1 (inclusive) that may allow arbitrary code execution with root privileges. Successful exploitation     has been demonstrated on 32-bit Linux/glibc systems with ASLR. Under lab conditions, the attack requires     on average 6-8 hours of continuous connections up to the maximum the server will accept. Exploitation on     64-bit systems is believed to be possible but has not been demonstrated at this time. It's likely that     these attacks will be improved upon. Exploitation on non-glibc systems is conceivable but has not been     examined. Systems that lack ASLR or users of downstream Linux distributions that have modified OpenSSH to     disable per-connection ASLR re-randomisation (yes - this is a thing, no - we don't understand why) may     potentially have an easier path to exploitation. OpenBSD is not vulnerable. We thank the Qualys Security     Advisory Team for discovering, reporting and demonstrating exploitability of this problem, and for     providing detailed feedback on additional mitigation measures. 2) Logic error in ssh(1)     ObscureKeystrokeTiming In OpenSSH version 9.5 through 9.7 (inclusive), when connected to an OpenSSH server     version 9.5 or later, a logic error in the ssh(1) ObscureKeystrokeTiming feature (on by default) rendered     this feature ineffective - a passive observer could still detect which network packets contained real     keystrokes when the countermeasure was active because both fake and real keystroke packets were being sent     unconditionally. This bug was Daniel Hugenroth and Alastair Beresford of the University of Cambridge     Computer Lab. Worse, the unconditional sending of both fake and real keystroke packets broke another long-     standing timing attack mitigation. Since OpenSSH 2.9.9 sshd(8) has sent fake keystoke echo packets for     traffic received on TTYs in echo-off mode, such as when entering a password into su(8) or sudo(8). This     bug rendered these fake keystroke echoes ineffective and could allow a passive observer of a SSH session     to once again detect when echo was off and obtain fairly limited timing information about keystrokes in     this situation (20ms granularity by default). This additional implication of the bug was identified by     Jacky Wei En Kung, Daniel Hugenroth and Alastair Beresford and we thank them for their detailed analysis.
    This bug does not affect connections when ObscureKeystrokeTiming was disabled or sessions where no TTY was     requested. (openssh-9.8-1)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Detections

Analytics

OpenSSH < 9.8 RCE

high Nessus Plugin ID 201194

Version 1.4

Version 1.3

Version 1.2

Version 1.1

Version 1.4 Jul 11, 2024, 3:59 PM Plugin metadata (add CVE-2024-39894) Plugin Feed: 202407111559
Version 1.3 Jul 5, 2024, 4:58 PM IAVM reference STIG Severity (set to "I") Plugin Feed: 202407051658
Version 1.2 Jul 2, 2024, 8:20 AM CVSS temporal metrics ("CVSSv2 temporal vector" set to "CVSS2#E:POC/RL:OF/RC:C") CVSS temporal metrics ("CVSSv3 temporal vector" set to "CVSS:3.0/E:P/RL:O/RC:C") Exploit attributes ("Exploit available" set to "True") Exploit attributes ("Exploitability ease" changed from "No known exploits are available" to "Exploits are available") Plugin Feed: 202407020820
Version 1.1 Jul 1, 2024, 4:07 PM New Plugin Feed: 202407011607