CVE-2019-1859
Cisco Small Business Switches Secure Shell Certificate Authentication Bypass Vulnerability
- Published
- Updated
- Reserved
- Assigned by
- cisco
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| ciscoCNA (assigner) | 3.0 | High7.2 | CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.2 | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.84% · top 42% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.2.
Weakness
Affected products
Cisco · Cisco Small Business 200 Series Smart Switches
- affected unspecified – < 1.4.10.6
- affected unspecified – < 2.5.0.78
What to do
Exploitation: The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.
References (1)
- 20190501 Cisco Small Business Switches Secure Shell Certificate Authentication Bypass Vulnerability (opens in a new tab)vendor-advisoryx_refsource_CISCOx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2019-1859)Record last updated .