CVE-2021-1243

mediumpriority · track · 30EPSS 0.013 · 70 %ileEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

1.27% (70th) EPSS

CVSS 5 · medium

Is it mine?

15 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · cisco_csaf

EPSS · scored 2026-10-27

A vulnerability in the Local Packet Transport Services (LPTS) programming of the SNMP with the management plane protection feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to allow connections despite the management plane protection that is configured to deny access to the SNMP server of an affected device. This vulnerability is due to incorrect LPTS programming when using SNMP with management plane protection. An attacker could exploit this vulnerability by connecting to an affected device using SNMP. A successful exploit could allow the attacker to connect to the device on the configured SNMP ports. Valid credentials are required to execute any of the SNMP requests.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedCisco IOS XR Softwarecisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com

cvss

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5–7.5

v2.05mediumAV:N/AC:L/Au:N/C:N/I:P/A:Nprimary · NVD / NIST USexploitability 10 · impact 2.9

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.15.3mediumAV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:Nsecondary · FSTEC (BDU) RU

v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:Nsecondary · ENISA EU

v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:Nsecondary · psirt@cisco.com USexploitability 3.9 · impact 1.4

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:Usecondary · CVSS-BT (t0sche)

v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:Nsecondary · Cisco PSIRT US

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-284USCWE-284US

affected products (15)

Products and version ranges known to be affected.

Cisco Cisco IOS XR Softwareall versionscisco_csafUS
Cisco Cisco IOS XR Software≤ n/aenisa_euvdEU
Cisco Systems Inc. Cisco IOS XR≤ 7.2.0fstec_bduRU
Cisco Systems Inc. Cisco IOS XR≤ 6.7.1fstec_bduRU
Cisco Systems Inc. Cisco IOS XR≤ 7.1.0fstec_bduRU
Cisco Systems Inc. Cisco IOS XR≤ 7.0.11fstec_bduRU
Cisco Systems Inc. Cisco IOS XR6.1.1 → 6.6.4fstec_bduRU
Cisco Systems Inc. Cisco IOS XR7.0.0 → 7.0.2fstec_bduRU
cisco ios xr< 6.6.4nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr6.1.1 → 6.6.4nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 6.7.1nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr7.0.0 → 7.0.2nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 7.0.11nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 7.1.0nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 7.2.0nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*

advisories (1)

Vendor and ecosystem advisories describing this.

cisco-sa-snmp-7MKrW7NqCisco IOS XR Software SNMP Management Plane Protection ACL Bypass Vulnerability2021-02-03csaf · cisco_csafUS
A vulnerability in the Local Packet Transport Services (LPTS) programming of the SNMP with the management plane protection feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to allow connections despite the management plane protection that is configured to deny access to the SNMP server of an affected device. This vulnerability is due to incorrect LPTS programming when using SNMP with management plane protection. An attacker could exploit this vulnerability by connecting to an affected device using SNMP. A successful exploit could allow the attacker to connect to the device on the configured SNMP ports. Valid credentials are required to execute any of the SNMP requests. Cisco has released software updates that address this vulnerability. There are workarounds that address this vulnerability.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cisco_csaf nvd NVD CVE.org MITRE

published 2021-02-04modified 2026-06-17

references (5)

External citations — patches, advisories, analysis.

scry

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