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NVD / CVE Program· CNA cisco

CVE-2021-1251: Cisco Small Business RV Series Routers Link Layer Discovery Protocol Vulnerabilities

HighCVSS 7.4 · v3.1—No exploit No fix recorded

Noroxi assessment

Priority: Monitor (action score 29/100)

  • 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: 0.45% (FIRST EPSS).
  • Someone on the same network segment can trigger it. No account or password is 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 2 times 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

Primary sources: NVD · CVE.org · FIRST EPSS

Multiple vulnerabilities exist in the Link Layer Discovery Protocol (LLDP) implementation for Cisco Small Business RV Series Routers. An unauthenticated, adjacent attacker could execute arbitrary code or cause an affected router to leak system memory or reload. A memory leak or device reload would cause a denial of service (DoS) condition on an affected device. For more information about these vulnerabilities, see the Details section of this advisory. Note: LLDP is a Layer 2 protocol. To exploit these vulnerabilities, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent).

Published
Apr 8, 2021
Updated
Jun 16, 2026
EPSS
0.4% · 39th percentile

Report tools

JSON

Action score

29

Monitor

Low priority for now.

CVSS
29 / 40 · 7.4 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
7.4
CNA · cisco
7.4
agree

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.

Follow CVE-2021-1251

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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.

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Affected 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.

VendorProduct
ciscorv132w firmware
ciscorv132w
ciscorv134w firmware
ciscorv134w
ciscorv160 firmware
ciscorv160
ciscorv160w firmware
ciscorv160w
ciscorv260 firmware
ciscorv260
ciscorv260p firmware
ciscorv260p

and 10 more

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 RV Series Router Firmware

    • n/aaffected
Affected versions · NVD (20)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • cisco rv132w firmware1.0.1.14
  • cisco rv132w firmware1.0.3.20
  • cisco rv134w firmware1.0.1.14
  • cisco rv134w firmware1.0.3.20
  • cisco rv160 firmware1.0.1.14
  • cisco rv160 firmware1.0.3.20
  • cisco rv160w firmware1.0.1.14
  • cisco rv160w firmware1.0.3.20
  • cisco rv260 firmware1.0.1.14
  • cisco rv260 firmware1.0.3.20
  • cisco rv260p firmware1.0.1.14
  • cisco rv260p firmware1.0.3.20
  • cisco rv260w firmware1.0.1.14
  • cisco rv260w firmware1.0.3.20
  • cisco rv340 firmware1.0.1.14
  • cisco rv340 firmware1.0.3.20
  • cisco rv340w firmware1.0.1.14
  • cisco rv340w firmware1.0.3.20
  • cisco rv345 firmware1.0.1.14
  • cisco rv345 firmware1.0.3.20

Same product

cisco: all records

Other highest-scoring records for the same primary product.

  • CVE-2018-0125A vulnerability in the web interface of the Cisco RV132W ADSL2+ Wireless-N VPN and RV134W VDSL2 Wireless-AC VPN Routers could allow an…KEV
    86Now
  • CVE-2018-0127A vulnerability in the web interface of Cisco RV132W ADSL2+ Wireless-N VPN Routers and Cisco RV134W VDSL2 Wireless-AC VPN Routers could…
    62This week
  • CVE-2021-1309Cisco Small Business RV Series Routers Link Layer Discovery Protocol Vulnerabilities
    35Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2021-1287Mar 18, 2021 · Cisco Small Business RV132W and RV134W Routers Management Interface Remote Command Execution and Denial of Service Vulnerability
    29Monitor
  • Later →CVE-2021-1308Apr 8, 2021 · Cisco Small Business RV Series Routers Link Layer Discovery Protocol Vulnerabilities
    29Monitor

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.

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Someone on the same network segment 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
Adjacent
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-119 · Improper Restriction of Operations within the Bounds of a Memory Buffer

CVSS vector

CVSS:3.1/AV:A/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.

ATT&CK techniques

—

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records