Cyber Resilience

CVE-2021-1243

Medium

Published: 04 February 2021

Published
04 February 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS Score 0.0061 70.2th percentile
Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-1243 is a medium-severity Improper Access Control (CWE-284) vulnerability in Cisco Ios Xr. Its CVSS base score is 5.3 (Medium).

Operationally, ranked in the top 29.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

more

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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

cisco
ios xr
6.7.1, 7.0.11, 7.1.0, 7.2.0 · 6.1.1 — 6.6.4 · 7.0.0 — 7.0.2

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-284

The access control policy and procedures directly mandate and enforce proper access control mechanisms across the organization.

addresses: CWE-284

Device lock enforces restricted access until re-authentication, directly reducing unauthorized use of active sessions.

addresses: CWE-284

Supervision and review of access control activities directly detects and remediates improper access configurations or usages.

addresses: CWE-284

Explicitly identifying and documenting actions permitted without identification or authentication enforces proper access control boundaries by defining justified exceptions.

addresses: CWE-284

By automatically labeling outputs with security attributes, the control supports attribute-based enforcement and reduces exploitability of improper access control weaknesses.

addresses: CWE-284

Associating and retaining security attributes with data directly supports enforcement of access control decisions across storage, processing, and transmission.

addresses: CWE-284

Requiring prior authorization for each remote access type prevents improper access control over remote connections.

addresses: CWE-284

Requiring authorization of wireless access before allowing connections enforces proper access control for this access method.

References