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Fencer Intel
high 7.2

CVE-2019-1859 json

Cisco Small Business Switches Secure Shell Certificate Authentication Bypass Vulnerability

published 7y ago modified 4mo ago also EUVD-2019-10416

cvss
7.2
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 58%
public exploits
0
none known

Summary

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.

Patch / fix

  • Cisco Cisco Small Business 200 Series Smart Switches 1.4.10.6, 2.5.0.78

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
last yr.

Exploit prediction

0.84% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.0 7.2 CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 7.2 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 6.5 AV:N/AC:L/Au:S/C:P/I:P/A:P

Affected products

  • Cisco Cisco Small Business 200 Series Smart Switches

Classification

Weakness
  • CWE-285 Improper Authorization
  • CWE-295 Improper Certificate Validation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.