CVE-2021-1540

Cisco ASR 5000 Series Software Authorization Bypass Vulnerabilities

HIGH

7.2

CVSS Score

Published: June 4, 2021 at 04:46 PM UTC

Updated: June 17, 2026 at 03:32 AM UTC

5 products affected across 1 vendorStarosVirtualized Packet CoreAsr 5000

Using Cisco ASR 5000 Series Software by Cisco?

Get instant alerts when new vulnerabilities affect Cisco ASR 5000 Series Software - before attackers find them.

Real-time alertsTrack your software stackFree plan available

Start Free Sign In

Severity

HIGH7.2

Exploit prediction

EPSS 1%

SSVC

No known exploit

Description

Multiple vulnerabilities in the authorization process of Cisco ASR 5000 Series Software (StarOS) could allow an authenticated, remote attacker to bypass authorization and execute a subset of CLI commands on an affected device. For more information about these vulnerabilities, see the Details section of this advisory.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Staros · Cisco

95%

v < 21.16.921.17.0 ≤ v < 21.17.1021.18.0 ≤ v < 21.18.1621.19.0 ≤ v < 21.19.1121.19.n ≤ v < 21.19.n721.20.0 ≤ v < 21.20.8

Affected range stops below 21.16.9, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.17.10, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.18.16, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.19.11, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.19.n7, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.20.8, so it looks safe — our inference, not a vendor statement

cisco-asr-5000 (environment) · cisco-asr-5500 (environment) · cisco-asr-5700 (environment)

Virtualized Packet Core · Cisco

95%

All versions

Asr 5000 · Ciscodevice

80%

All versions

Asr 5500 · Ciscodevice

80%

All versions

Asr 5700 · Ciscodevice

80%

All versions

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asr5k-autho-bypass-mJDF5S7n

References (1)

Vendor Advisoryx_refsource_CISCO

Source: [email protected]

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asr5k-autho-bypass-mJDF5S7n

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.2HIGH[email protected]

Attack Vector: NETWORK
Complexity: LOW
Privileges: HIGH
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: HIGH
Integrity: HIGH
Availability: HIGH

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-863

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Create account Sign in

Free plan, no card