Cisco Small Business Switches Secure Shell Certificate Authentication Bypass Vulnerability
Noroxi assessment
Priority: Monitor (action score 28/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.83% (FIRST EPSS); higher than 56.6% of all records.
- Anyone who can reach it over the internet can trigger it. Administrator privileges are required. No user action is required. No special conditions are required; it is repeatable.
- According to the record, no fixed version is available yet.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Update when a fix is released; follow the vendor's advisory.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
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.
- Published
- May 3, 2019
- Updated
- Jun 16, 2026
- EPSS
- 0.8% · 57th percentile
- CWE
- CWE-285
Report tools
Action score
28
Monitor
Low priority for now.
- CVSS
- 28 / 40 · 7.2 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.8%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 7.2
- CNA · cisco
- 7.2
- agree
CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- No fixed version yet
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| cisco | sg200-50 firmware | cpe:2.3:o:cisco:sg200-50_firmware |
| cisco | sg200-50 | cpe:2.3:h:cisco:sg200-50 |
| cisco | sg200-50p firmware | cpe:2.3:o:cisco:sg200-50p_firmware |
| cisco | sg200-50p | cpe:2.3:h:cisco:sg200-50p |
| cisco | sg200-50fp firmware | cpe:2.3:o:cisco:sg200-50fp_firmware |
| cisco | sg200-50fp | cpe:2.3:h:cisco:sg200-50fp |
| cisco | sg200-26 firmware | cpe:2.3:o:cisco:sg200-26_firmware |
| cisco | sg200-26 | cpe:2.3:h:cisco:sg200-26 |
| cisco | sg200-26p firmware | cpe:2.3:o:cisco:sg200-26p_firmware |
| cisco | sg200-26p | cpe:2.3:h:cisco:sg200-26p |
| cisco | sg200-26fp firmware | cpe:2.3:o:cisco:sg200-26fp_firmware |
| cisco | sg200-26fp | cpe:2.3:h:cisco:sg200-26fp |
and 188 more
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- cisco sf200-24 firmwarebefore 1.4.10.6
- cisco sf200-24fp firmwarebefore 1.4.10.6
- cisco sf200-24p firmwarebefore 1.4.10.6
- cisco sf200-48 firmwarebefore 1.4.10.6
- cisco sf200-48p firmwarebefore 1.4.10.6
- cisco sf250-24 firmwarebefore 2.5.0.78
- cisco sf250-24p firmwarebefore 2.5.0.78
- cisco sf250-48 firmwarebefore 2.5.0.78
- cisco sf250-48hp firmwarebefore 2.5.0.78
- cisco sf300-08 firmwarebefore 1.4.10.6
- cisco sf300-24 firmwarebefore 1.4.10.6
- cisco sf300-24mp firmwarebefore 1.4.10.6
- cisco sf300-24p firmwarebefore 1.4.10.6
- cisco sf300-24pp firmwarebefore 1.4.10.6
- cisco sf300-48 firmwarebefore 1.4.10.6
- cisco sf300-48p firmwarebefore 1.4.10.6
- cisco sf300-48pp firmwarebefore 1.4.10.6
- cisco sf302-08 firmwarebefore 1.4.10.6
- cisco sf302-08mp firmwarebefore 1.4.10.6
- cisco sf302-08mpp firmwarebefore 1.4.10.6
Versions reported by the vendor
Affected version ranges reported by the assigning authority (cisco). Independent of NVD's CPE analysis and usually ahead of it.
Cisco Cisco Small Business 200 Series Smart Switches
- unspecified and later · before 1.4.10.6affected
- unspecified and later · before 2.5.0.78affected
Same product
cisco: all recordsOther highest-scoring records for the same primary product.
- CVE-2018-15439Cisco Small Business Switches Privileged Access Vulnerability54Plan
- CVE-2020-3147Cisco Small Business Switches Denial of Service Vulnerability31Monitor
- CVE-2019-1943Cisco Small Business Series Switches Open Redirect Vulnerability27Monitor
- CVE-2020-3496Cisco Small Business Smart and Managed Switches Denial of Service Vulnerability22Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-19-049 · May 1, 2019(Cisco Güvenlik Güncellemesi Yayınladı)
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- Administrator privileges are required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-285 · Improper AuthorizationCVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Accessing Functionality Not Properly Constrained by ACLsCAPEC-1likelihood: High · High
- Cross Zone ScriptingCAPEC-104likelihood: Medium · High
- Directory IndexingCAPEC-127likelihood: High · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
- Using Malicious FilesCAPEC-17likelihood: High · Very High
- Manipulating Opaque Client-based Data TokensCAPEC-39likelihood: High · Medium
- Bypassing ATA Password SecurityCAPEC-402
- Buffer Overflow via Symbolic LinksCAPEC-45likelihood: High · High
ATT&CK techniques
- Data from Local SystemT1005
- Query RegistryT1012
- File and Directory DiscoveryT1083
- Access Token Manipulation:Token Impersonation/TheftT1134.001
- Use Alternate Authentication Material:Web Session CookieT1550.004
- Unsecured Credentials: Credentials in RegistryT1552.002
- Impair Defenses:Impair Command History LoggingT1562.003
- Data Manipulation: Transmitted Data ManipulationT1565.002
- Hijack Execution Flow: Executable Installer File Permissions WeaknessT1574.005
- Hijack Execution Flow:Dynamic Linker HijackingT1574.006
- Hijack Execution Flow:Path Interception by PATH Environment VariableT1574.007
- Hijack Execution Flow: ServicesFile Permissions WeaknessT1574.010
Change log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.