CVE-2019-1859

Cisco Small Business Switches Secure Shell Certificate Authentication Bypass Vulnerability

HIGH
7.2
CVSS Score
Published: May 3, 2019 at 04:40 PM UTC
Updated: June 17, 2026 at 02:29 AM UTC
229 products affected across 1 vendorSg300-10pp FirmwareSg300-28mp FirmwareSf300-48pp Firmware

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Severity
HIGH7.2
Exploit prediction
EPSS 0.8%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.4.10.6
Affected range stops below 1.4.10.6, so it looks safe — our inference, not a vendor statement
cisco-sf200-24 (same device)
v < 1.4.10.6
Affected range stops below 1.4.10.6, so it looks safe — our inference, not a vendor statement
cisco-sf200-24fp (same device)
v < 1.4.10.6
Affected range stops below 1.4.10.6, so it looks safe — our inference, not a vendor statement
cisco-sf200-24p (same device)
v < 1.4.10.6
Affected range stops below 1.4.10.6, so it looks safe — our inference, not a vendor statement
cisco-sf200-48 (same device)
v < 1.4.10.6
Affected range stops below 1.4.10.6, so it looks safe — our inference, not a vendor statement
cisco-sf200-48p (same device)
v < 2.5.0.78
Affected range stops below 2.5.0.78, so it looks safe — our inference, not a vendor statement
cisco-sf250-24 (same device)
v < 2.5.0.78
Affected range stops below 2.5.0.78, so it looks safe — our inference, not a vendor statement
cisco-sf250-24p (same device)
v < 2.5.0.78
Affected range stops below 2.5.0.78, so it looks safe — our inference, not a vendor statement
cisco-sf250-48 (same device)
v < 2.5.0.78
Affected range stops below 2.5.0.78, so it looks safe — our inference, not a vendor statement
cisco-sf250-48hp (same device)
v < 1.4.10.6
Affected range stops below 1.4.10.6, so it looks safe — our inference, not a vendor statement
cisco-sf300-08 (same device)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-285CWE-295

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