high
7.2
CWE
295 285
Advisory Published
Updated

CVE-2019-1859: Cisco Small Business Switches Secure Shell Certificate Authentication Bypass Vulnerability

First published: Fri May 03 2019(Updated: )

A vulnerability in the Secure Shell (SSH) authentication process of Cisco Small Business Switches software could allow an attacker to bypass client-side certificate authentication and revert to password authentication. The vulnerability exists because OpenSSH mishandles the authentication process. An attacker could exploit this vulnerability by attempting to connect to the device via SSH. A successful exploit could allow the attacker to access the configuration as an administrative user if the default credentials are not changed. There are no workarounds available; however, if client-side certificate authentication is enabled, disable it and use strong password authentication. Client-side certificate authentication is disabled by default.

Credit: ykramarz@cisco.com ykramarz@cisco.com

Affected SoftwareAffected VersionHow to fix
Cisco SG200-50P Firmware<1.4.10.6
Cisco SG200-50FP
Cisco SG200-50P Firmware<1.4.10.6
Cisco SG200-50P Firmware
Cisco SG200-50 Firmware<1.4.10.6
Cisco SG200-50 Firmware
Cisco SG200-26P Firmware<1.4.10.6
Cisco SG200-26P Firmware
Cisco SG200-26 Firmware<1.4.10.6
Cisco SG200-26P Firmware
Cisco SG200-26FP Firmware<1.4.10.6
Cisco SG200-26FP Firmware
Cisco SG200-18 Firmware<1.4.10.6
Cisco SG200-18 Firmware
Cisco SG200-10FP Firmware<1.4.10.6
Cisco SG200-10FP Firmware
Cisco SG200-08<1.4.10.6
Cisco SG200-08 Firmware
Cisco SG200-08P Firmware<1.4.10.6
Cisco SG200-08P Firmware
Cisco SF200-24 Firmware<1.4.10.6
Cisco SF200-24P
Cisco SF200-24P Firmware<1.4.10.6
Cisco SF200-24P Firmware
Cisco SF200-24FP Firmware<1.4.10.6
Cisco SF200-24FP Firmware
Cisco SF200-48 Firmware<1.4.10.6
Cisco SF200-48 Firmware
Cisco SF200-48P Firmware<1.4.10.6
Cisco SF200-48P Firmware
Cisco SF302-08<1.4.10.6
Cisco SF302-08
Cisco SF302-08<1.4.10.6
Cisco SF302-08
Cisco SG300-10PP<1.4.10.6
Cisco SG300-10 Firmware
Cisco SG300-10MPP Firmware<1.4.10.6
Cisco SG300-10MPP Firmware
Cisco SF300-24P<1.4.10.6
Cisco SF300-24PP Firmware
Cisco SF300-48PP Firmware<1.4.10.6
Cisco SF300-48PP Firmware
Cisco SG300-28PP Firmware<1.4.10.6
Cisco SG300-28PP Firmware
Cisco SF300-08 Firmware<1.4.10.6
Cisco SF300-08 Firmware
Cisco SF300-48P Firmware<1.4.10.6
Cisco SF300-48P Firmware
Cisco SG300-10MP Firmware<1.4.10.6
Cisco SG300-10MP Firmware
Cisco SG300-10P Firmware<1.4.10.6
Cisco SG300-10P Firmware
Cisco SG300 Series Firmware<1.4.10.6
Cisco SG300-10 Firmware
Cisco SG300-28P Firmware<1.4.10.6
Cisco SG300-28P
Cisco SF300-24P<1.4.10.6
Cisco SF300-24 Firmware
Cisco SF302-08<1.4.10.6
Cisco SF302-08
Cisco SG300-28P<1.4.10.6
Cisco SG300-28 Firmware
Cisco SF300-48P Firmware<1.4.10.6
Cisco SF300-48P
Cisco SG300 Series Firmware<1.4.10.6
Cisco SG300-20 Firmware
Cisco SF302-08P<1.4.10.6
Cisco SF302-08
Cisco SG300 Series Firmware<1.4.10.6
Cisco SG300-52P
Cisco SF300-24P Firmware<1.4.10.6
Cisco SF300-24 Firmware
Cisco SF302-08 Firmware<1.4.10.6
Cisco SF302-08 Firmware
Cisco SF300-24MP Firmware<1.4.10.6
Cisco SF300-24MP Firmware
Cisco SG300 Series Firmware<1.4.10.6
Cisco SG300-10SFP Firmware
Cisco SG300-28MP<1.4.10.6
Cisco SG300-28MP
Cisco SG300-52P Firmware<1.4.10.6
Cisco SG300-52P Firmware
Cisco SG300-52MP Firmware<1.4.10.6
Cisco SG300-52MP Firmware
Cisco SG500-28PP Firmware<1.4.10.6
Cisco SG500-28MPP Firmware
Cisco SG500-52MP<1.4.10.6
Cisco SG500-52
Cisco SG500XG-8F8T<1.4.10.6
Cisco SG500XG-8F8T Firmware
Cisco SF500-24<1.4.10.6
Cisco SF500-24MP
Cisco SF500-24P<1.4.10.6
Cisco SF500-24P Firmware
Cisco SF500-48P Firmware<1.4.10.6
Cisco SF500-48 Firmware
Cisco 500 Series Switch Firmware<1.4.10.6
Cisco SF500-48 Firmware
Cisco SG500-28<1.4.10.6
Cisco SG500-28PP Firmware
Cisco SG500-28P<1.4.10.6
Cisco SG500-28P
Cisco SG500-52P<1.4.10.6
Cisco SG500-52 Firmware
Cisco SG500-52P<1.4.10.6
Cisco SG500-52P
Cisco SG500X-24<1.4.10.6
Cisco SG500X-24P
Cisco SG500X-24P<1.4.10.6
Cisco SG500X-24P
Cisco SG500X-48<1.4.10.6
Cisco SG500X-48MP Firmware
Cisco SG500X-48P<1.4.10.6
Cisco SG500X-48P
Cisco SG250X-24P Firmware<2.5.0.78
Cisco SG250X-24 Firmware
Cisco SG250X-24 Firmware<2.5.0.78
Cisco SG250X-24P Firmware
Cisco SG250X-48P Firmware<2.5.0.78
Cisco SG250X-48 Firmware
Cisco SG250X-48P Firmware<2.5.0.78
Cisco SG250X-48P Firmware
Cisco SG250-08HP Firmware<2.5.0.78
Cisco SG250-08HP Firmware
Cisco SG250-08HP Firmware<2.5.0.78
Cisco SG250-08HP Firmware
Cisco SG250-10P Firmware<2.5.0.78
Cisco SG250-10P
Cisco SG250-18<2.5.0.78
Cisco SG250-18 Firmware
Cisco SG250-26P Firmware<2.5.0.78
Cisco SG250-26 Firmware
Cisco SG250-26HP<2.5.0.78
Cisco SG250-26HP Firmware
Cisco SG250-26P Firmware<2.5.0.78
Cisco SG250-26P Firmware
Cisco SG250-50P Firmware<2.5.0.78
Cisco SG250-50 Firmware
Cisco SG250-50HP Firmware<2.5.0.78
Cisco SG250-50HP Firmware
Cisco SG250-50P Firmware<2.5.0.78
Cisco SG250-50P Firmware
Cisco SF250-24 Firmware<2.5.0.78
Cisco SF250-24 Firmware
Cisco SF250-24P Firmware<2.5.0.78
Cisco SF250-24P Firmware
Cisco SF250-48<2.5.0.78
Cisco SF250-48HP Firmware
Cisco SF250-48HP Firmware<2.5.0.78
Cisco SF250-48HP Firmware
Cisco SG350-10P<2.5.0.78
Cisco SG350-10 Firmware
Cisco SG350-10P<2.5.0.78
Cisco SG350-10P
Cisco SG350-10MP Firmware<2.5.0.78
Cisco SG350-10MP Firmware
Cisco SG355-10P<2.5.0.78
Cisco SG355-10P
Cisco SG350-28P Firmware<2.5.0.78
Cisco SG350-28 Firmware
Cisco SG350-28P Firmware<2.5.0.78
Cisco SG350-28P Firmware
Cisco SG350-28MP Firmware<2.5.0.78
Cisco SG350-28MP Firmware
Cisco SF350-48 Firmware<2.5.0.78
Cisco SF350-48 Firmware
Cisco SF350-48P Firmware<2.5.0.78
Cisco SF350-48P Firmware
Cisco SF350-48MP Firmware<2.5.0.78
Cisco SF350-48MP Firmware
Cisco SG350XG-2F10<2.5.0.78
Cisco SG350XG-2F10 Firmware
Cisco SG350XG-24F Firmware<2.5.0.78
Cisco SG350XG-24F Firmware
Cisco SG350XG-24F Firmware<2.5.0.78
Cisco SG350XG-24F Firmware
Cisco SG350XG-48T Firmware<2.5.0.78
Cisco SG350XG-48T Firmware
Cisco SG350X-24P Firmware<2.5.0.78
Cisco SG350X-24 Firmware
Cisco SG350X-24 Firmware<2.5.0.78
Cisco SG350X-24 Firmware
Cisco SG350X-24MP<2.5.0.78
Cisco SG350X-24MP Firmware
Cisco SG350X-48 Firmware<2.5.0.78
Cisco SG350X-48 Firmware
Cisco SG350X-48P Firmware<2.5.0.78
Cisco SG350X-48P Firmware
Cisco SG350X-48MP<2.5.0.78
Cisco SG350X-48MP Firmware
Cisco SX550X Firmware<2.5.0.78
Cisco SX550X-16FT Firmware
Cisco SX550X Firmware<2.5.0.78
Cisco SX550X-24FT Firmware
Cisco SX550X-12F Firmware<2.5.0.78
Cisco SX550X-12F Firmware
Cisco SX550X Firmware<2.5.0.78
Cisco SX550X-24F Firmware
Cisco SX550X Firmware<2.5.0.78
Cisco SX550X-24F Firmware
Cisco SX550X-52<2.5.0.78
Cisco SX550X-52
Cisco SG550X-24P Firmware<2.5.0.78
Cisco SG550X-24 Firmware
Cisco SG550X-24P Firmware<2.5.0.78
Cisco SG550X-24P Firmware
Cisco SG550X-24MP Firmware<2.5.0.78
Cisco SG550X-24MP Firmware
Cisco SG550X-24MPP Firmware<2.5.0.78
Cisco SG550X-24MPP Firmware
Cisco SG550X-48MP Firmware<2.5.0.78
Cisco SG550X-48 Firmware
Cisco SG550X-48P Firmware<2.5.0.78
Cisco SG550X-48P Firmware
Cisco SG550X-48MP Firmware<2.5.0.78
Cisco SG550X-48MP Firmware
Cisco SF550X-24P<2.5.0.78
Cisco SF550X-24 Firmware
Cisco SF550X-24P<2.5.0.78
Cisco SF550X-24P Firmware
Cisco SF550X-24MP Firmware<2.5.0.78
Cisco SF550X-24MP Firmware
Cisco SF550X-48<2.5.0.78
Cisco SF550X-48 Firmware
Cisco SF550X-48P Firmware<2.5.0.78
Cisco SG550X-48P
Cisco SG550X-48MP Firmware<2.5.0.78
Cisco SF550X-48MP Firmware
All of
Cisco SG200-50P Firmware<1.4.10.6
Cisco SG200-50FP
All of
Cisco SG200-50P Firmware<1.4.10.6
Cisco SG200-50P Firmware
All of
Cisco SG200-50 Firmware<1.4.10.6
Cisco SG200-50 Firmware
All of
Cisco SG200-26P Firmware<1.4.10.6
Cisco SG200-26P Firmware
All of
Cisco SG200-26 Firmware<1.4.10.6
Cisco SG200-26P Firmware
All of
Cisco SG200-26FP Firmware<1.4.10.6
Cisco SG200-26FP Firmware
All of
Cisco SG200-18 Firmware<1.4.10.6
Cisco SG200-18 Firmware
All of
Cisco SG200-10FP Firmware<1.4.10.6
Cisco SG200-10FP Firmware
All of
Cisco SG200-08<1.4.10.6
Cisco SG200-08 Firmware
All of
Cisco SG200-08P Firmware<1.4.10.6
Cisco SG200-08P Firmware
All of
Cisco SF200-24 Firmware<1.4.10.6
Cisco SF200-24P
All of
Cisco SF200-24P Firmware<1.4.10.6
Cisco SF200-24P Firmware
All of
Cisco SF200-24FP Firmware<1.4.10.6
Cisco SF200-24FP Firmware
All of
Cisco SF200-48 Firmware<1.4.10.6
Cisco SF200-48 Firmware
All of
Cisco SF200-48P Firmware<1.4.10.6
Cisco SF200-48P Firmware
All of
Cisco SF302-08<1.4.10.6
Cisco SF302-08
All of
Cisco SF302-08<1.4.10.6
Cisco SF302-08
All of
Cisco SG300-10PP<1.4.10.6
Cisco SG300-10 Firmware
All of
Cisco SG300-10MPP Firmware<1.4.10.6
Cisco SG300-10MPP Firmware
All of
Cisco SF300-24P<1.4.10.6
Cisco SF300-24PP Firmware
All of
Cisco SF300-48PP Firmware<1.4.10.6
Cisco SF300-48PP Firmware
All of
Cisco SG300-28PP Firmware<1.4.10.6
Cisco SG300-28PP Firmware
All of
Cisco SF300-08 Firmware<1.4.10.6
Cisco SF300-08 Firmware
All of
Cisco SF300-48P Firmware<1.4.10.6
Cisco SF300-48P Firmware
All of
Cisco SG300-10MP Firmware<1.4.10.6
Cisco SG300-10MP Firmware
All of
Cisco SG300-10P Firmware<1.4.10.6
Cisco SG300-10P Firmware
All of
Cisco SG300 Series Firmware<1.4.10.6
Cisco SG300-10 Firmware
All of
Cisco SG300-28P Firmware<1.4.10.6
Cisco SG300-28P
All of
Cisco SF300-24P<1.4.10.6
Cisco SF300-24 Firmware
All of
Cisco SF302-08<1.4.10.6
Cisco SF302-08
All of
Cisco SG300-28P<1.4.10.6
Cisco SG300-28 Firmware
All of
Cisco SF300-48P Firmware<1.4.10.6
Cisco SF300-48P
All of
Cisco SG300 Series Firmware<1.4.10.6
Cisco SG300-20 Firmware
All of
Cisco SF302-08P<1.4.10.6
Cisco SF302-08
All of
Cisco SG300 Series Firmware<1.4.10.6
Cisco SG300-52P
All of
Cisco SF300-24P Firmware<1.4.10.6
Cisco SF300-24 Firmware
All of
Cisco SF302-08 Firmware<1.4.10.6
Cisco SF302-08 Firmware
All of
Cisco SF300-24MP Firmware<1.4.10.6
Cisco SF300-24MP Firmware
All of
Cisco SG300 Series Firmware<1.4.10.6
Cisco SG300-10SFP Firmware
All of
Cisco SG300-28MP<1.4.10.6
Cisco SG300-28MP
All of
Cisco SG300-52P Firmware<1.4.10.6
Cisco SG300-52P Firmware
All of
Cisco SG300-52MP Firmware<1.4.10.6
Cisco SG300-52MP Firmware
All of
Cisco SG500-28PP Firmware<1.4.10.6
Cisco SG500-28MPP Firmware
All of
Cisco SG500-52MP<1.4.10.6
Cisco SG500-52
All of
Cisco SG500XG-8F8T<1.4.10.6
Cisco SG500XG-8F8T Firmware
All of
Cisco SF500-24<1.4.10.6
Cisco SF500-24MP
All of
Cisco SF500-24P<1.4.10.6
Cisco SF500-24P Firmware
All of
Cisco SF500-48P Firmware<1.4.10.6
Cisco SF500-48 Firmware
All of
Cisco 500 Series Switch Firmware<1.4.10.6
Cisco SF500-48 Firmware
All of
Cisco SG500-28<1.4.10.6
Cisco SG500-28PP Firmware
All of
Cisco SG500-28P<1.4.10.6
Cisco SG500-28P
All of
Cisco SG500-52P<1.4.10.6
Cisco SG500-52 Firmware
All of
Cisco SG500-52P<1.4.10.6
Cisco SG500-52P
All of
Cisco SG500X-24<1.4.10.6
Cisco SG500X-24P
All of
Cisco SG500X-24P<1.4.10.6
Cisco SG500X-24P
All of
Cisco SG500X-48<1.4.10.6
Cisco SG500X-48MP Firmware
All of
Cisco SG500X-48P<1.4.10.6
Cisco SG500X-48P
All of
Cisco SG250X-24P Firmware<2.5.0.78
Cisco SG250X-24 Firmware
All of
Cisco SG250X-24 Firmware<2.5.0.78
Cisco SG250X-24P Firmware
All of
Cisco SG250X-48P Firmware<2.5.0.78
Cisco SG250X-48 Firmware
All of
Cisco SG250X-48P Firmware<2.5.0.78
Cisco SG250X-48P Firmware
All of
Cisco SG250-08HP Firmware<2.5.0.78
Cisco SG250-08HP Firmware
All of
Cisco SG250-08HP Firmware<2.5.0.78
Cisco SG250-08HP Firmware
All of
Cisco SG250-10P Firmware<2.5.0.78
Cisco SG250-10P
All of
Cisco SG250-18<2.5.0.78
Cisco SG250-18 Firmware
All of
Cisco SG250-26P Firmware<2.5.0.78
Cisco SG250-26 Firmware
All of
Cisco SG250-26HP<2.5.0.78
Cisco SG250-26HP Firmware
All of
Cisco SG250-26P Firmware<2.5.0.78
Cisco SG250-26P Firmware
All of
Cisco SG250-50P Firmware<2.5.0.78
Cisco SG250-50 Firmware
All of
Cisco SG250-50HP Firmware<2.5.0.78
Cisco SG250-50HP Firmware
All of
Cisco SG250-50P Firmware<2.5.0.78
Cisco SG250-50P Firmware
All of
Cisco SF250-24 Firmware<2.5.0.78
Cisco SF250-24 Firmware
All of
Cisco SF250-24P Firmware<2.5.0.78
Cisco SF250-24P Firmware
All of
Cisco SF250-48<2.5.0.78
Cisco SF250-48HP Firmware
All of
Cisco SF250-48HP Firmware<2.5.0.78
Cisco SF250-48HP Firmware
All of
Cisco SG350-10P<2.5.0.78
Cisco SG350-10 Firmware
All of
Cisco SG350-10P<2.5.0.78
Cisco SG350-10P
All of
Cisco SG350-10MP Firmware<2.5.0.78
Cisco SG350-10MP Firmware
All of
Cisco SG355-10P<2.5.0.78
Cisco SG355-10P
All of
Cisco SG350-28P Firmware<2.5.0.78
Cisco SG350-28 Firmware
All of
Cisco SG350-28P Firmware<2.5.0.78
Cisco SG350-28P Firmware
All of
Cisco SG350-28MP Firmware<2.5.0.78
Cisco SG350-28MP Firmware
All of
Cisco SF350-48 Firmware<2.5.0.78
Cisco SF350-48 Firmware
All of
Cisco SF350-48P Firmware<2.5.0.78
Cisco SF350-48P Firmware
All of
Cisco SF350-48MP Firmware<2.5.0.78
Cisco SF350-48MP Firmware
All of
Cisco SG350XG-2F10<2.5.0.78
Cisco SG350XG-2F10 Firmware
All of
Cisco SG350XG-24F Firmware<2.5.0.78
Cisco SG350XG-24F Firmware
All of
Cisco SG350XG-24F Firmware<2.5.0.78
Cisco SG350XG-24F Firmware
All of
Cisco SG350XG-48T Firmware<2.5.0.78
Cisco SG350XG-48T Firmware
All of
Cisco SG350X-24P Firmware<2.5.0.78
Cisco SG350X-24 Firmware
All of
Cisco SG350X-24 Firmware<2.5.0.78
Cisco SG350X-24 Firmware
All of
Cisco SG350X-24MP<2.5.0.78
Cisco SG350X-24MP Firmware
All of
Cisco SG350X-48 Firmware<2.5.0.78
Cisco SG350X-48 Firmware
All of
Cisco SG350X-48P Firmware<2.5.0.78
Cisco SG350X-48P Firmware
All of
Cisco SG350X-48MP<2.5.0.78
Cisco SG350X-48MP Firmware
All of
Cisco SX550X Firmware<2.5.0.78
Cisco SX550X-16FT Firmware
All of
Cisco SX550X Firmware<2.5.0.78
Cisco SX550X-24FT Firmware
All of
Cisco SX550X-12F Firmware<2.5.0.78
Cisco SX550X-12F Firmware
All of
Cisco SX550X Firmware<2.5.0.78
Cisco SX550X-24F Firmware
All of
Cisco SX550X Firmware<2.5.0.78
Cisco SX550X-24F Firmware
All of
Cisco SX550X-52<2.5.0.78
Cisco SX550X-52
All of
Cisco SG550X-24P Firmware<2.5.0.78
Cisco SG550X-24 Firmware
All of
Cisco SG550X-24P Firmware<2.5.0.78
Cisco SG550X-24P Firmware
All of
Cisco SG550X-24MP Firmware<2.5.0.78
Cisco SG550X-24MP Firmware
All of
Cisco SG550X-24MPP Firmware<2.5.0.78
Cisco SG550X-24MPP Firmware
All of
Cisco SG550X-48MP Firmware<2.5.0.78
Cisco SG550X-48 Firmware
All of
Cisco SG550X-48P Firmware<2.5.0.78
Cisco SG550X-48P Firmware
All of
Cisco SG550X-48MP Firmware<2.5.0.78
Cisco SG550X-48MP Firmware
All of
Cisco SF550X-24P<2.5.0.78
Cisco SF550X-24 Firmware
All of
Cisco SF550X-24P<2.5.0.78
Cisco SF550X-24P Firmware
All of
Cisco SF550X-24MP Firmware<2.5.0.78
Cisco SF550X-24MP Firmware
All of
Cisco SF550X-48<2.5.0.78
Cisco SF550X-48 Firmware
All of
Cisco SF550X-48P Firmware<2.5.0.78
Cisco SG550X-48P
All of
Cisco SG550X-48MP Firmware<2.5.0.78
Cisco SF550X-48MP Firmware

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Reference Links

Frequently Asked Questions

  • What is the severity of CVE-2019-1859?

    The severity of CVE-2019-1859 is classified as high due to its potential impact on the SSH authentication process.

  • How do I fix CVE-2019-1859?

    To fix CVE-2019-1859, update your Cisco Small Business Switch to a firmware version that is not affected, specifically version 1.4.10.6 or later.

  • Which software versions are affected by CVE-2019-1859?

    CVE-2019-1859 currently affects Cisco SG200, SG300, SF200, SF300, and related models running firmware versions prior to 1.4.10.6.

  • What can an attacker do if CVE-2019-1859 is exploited?

    If exploited, an attacker could bypass client-side certificate authentication, reverting to password authentication, which increases the risk of unauthorized access.

  • Is CVE-2019-1859 remote or local attack vector?

    The CVE-2019-1859 vulnerability can potentially be exploited remotely, allowing attackers to access affected systems without physical presence.

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