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CVE-2020-3363· NVD / CVE Program· CNA cisco

Cisco Small Business Smart and Managed Switches Denial of Service Vulnerability

A vulnerability in the IPv6 packet processing engine of Cisco Small Business Smart and Managed Switches could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient validation of incoming IPv6 traffic. An attacker could exploit this vulnerability by sending a crafted IPv6 packet through an affected device. A successful exploit could allow the attacker to cause an unexpected reboot of the switch, leading to a DoS condition. This vulnerability is specific to IPv6 traffic. IPv4 traffic is not affected.

HighCVSS 8.6 · v3.1—No exploit No fix recorded
Published
Aug 17, 2020
Updated
Jun 16, 2026
EPSS
1.8% · 78th percentile
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JSON

Action score

35

Monitor

Low priority for now.

CVSS
34 / 40 · 8.6 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 1.8%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
8.6
CNA · cisco
8.6
agree

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Affected systems

VendorProduct
ciscosg250x-24 firmware
ciscosg250x-24
ciscosg250x-24p firmware
ciscosg250x-24p
ciscosg250x-48 firmware
ciscosg250x-48
ciscosg250x-48p firmware
ciscosg250x-48p
ciscosg250-08 firmware
ciscosg250-08
ciscosg250-08hp firmware
ciscosg250-08hp

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 firmwareall versions
  • cisco sf200-24fp firmwareall versions
  • cisco sf200-24p firmwareall versions
  • cisco sf200-48 firmwareall versions
  • cisco sf200-48p firmwareall versions
  • cisco sf250-24 firmwareall versions
  • cisco sf250-24p firmwareall versions
  • cisco sf250-48 firmwareall versions
  • cisco sf250-48hp firmwareall versions
  • cisco sf300-08 firmwareall versions
  • cisco sf300-24 firmwareall versions
  • cisco sf300-24mp firmwareall versions
  • cisco sf300-24p firmwareall versions
  • cisco sf300-24pp firmwareall versions
  • cisco sf300-48 firmwareall versions
  • cisco sf300-48p firmwareall versions
  • cisco sf300-48pp firmwareall versions
  • cisco sf302-08 firmwareall versions
  • cisco sf302-08mp firmwareall versions
  • cisco sf302-08mpp firmwareall versions

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 250 Series Smart Switches Software

    • n/aaffected

Same product

cisco: all records

Other highest-scoring records for the same primary product.

  • CVE-2020-3297Cisco Small Business Smart and Managed Switches Session Management Vulnerability
    40Plan
  • CVE-2019-15993Cisco Small Business Switches Information Disclosure Vulnerability
    24Monitor
  • CVE-2020-3121Cisco Small Business Smart and Managed Switches Cross-Site Scripting Vulnerability
    24Monitor

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.

EPSS, last 120 days

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 researchers

Finders, 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).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted

Impact can extend beyond the vulnerable component (scope changes).

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-20 · Improper Input Validation

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/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.

Noroxi analysis

No Noroxi analysis for this record yet

We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.

We use this product, ask for help

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.

All records