CVE-2021-1370

Root privilege escalation via crafted CLI arguments

Published Feb 4, 2021 · Updated Nov 8, 2024

OS command injection in Cisco IOS XR Software allows local users with valid device accounts to elevate privileges to root through a CLI command. An affected CLI command insufficiently validates command-line arguments before passing crafted input into operating-system command execution. Reachability requires an authenticated low-privilege session on an affected Cisco 8000 Series router or NCS 540 Series router using an NCS540L image; successful exploitation grants full root control.

CVSS severity7.8
High
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in Cisco IOS XR Software allows local users with valid device accounts to elevate privileges to root through a CLI command. An affected CLI command insufficiently validates command-line arguments before passing crafted input into operating-system command execution. Reachability requires an authenticated low-privilege session on an affected Cisco 8000 Series router or NCS 540 Series router using an NCS540L image; successful exploitation grants full root control.

The record

CVE
CVE-2021-1370
Published
Feb 4, 2021
Updated
Nov 8, 2024
Vendor
ClamAV
Product
Cisco IOS XR Software
Classifications
CWE-78, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 4, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 8, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=n/a

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

ClamAV · Cisco IOS XR Softwareversion=n/a

Published CVSS scores

7.8Cisco Systems, Inc.CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:X/RL:X/RC:X

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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