CVE-2021-1531Public exploitNetwork attack vector

Authenticated command execution via upload filename header

Published May 22, 2021 · Updated Nov 8, 2024

Command injection in Cisco Modeling Labs 2.0.0 through 2.1.3 allows remote authenticated users to execute commands through the web UI. The image-upload endpoint passes the X-Original-File-Name header into command processing without neutralizing argument delimiters. A valid web UI account with file-upload access is required, and injected commands run as the virl2 web-application user.

CVSS severity8.8
High
EPSS probability30.49%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection in Cisco Modeling Labs 2.0.0 through 2.1.3 allows remote authenticated users to execute commands through the web UI. The image-upload endpoint passes the X-Original-File-Name header into command processing without neutralizing argument delimiters. A valid web UI account with file-upload access is required, and injected commands run as the virl2 web-application user.

The record

CVE
CVE-2021-1531
Published
May 22, 2021
Updated
Nov 8, 2024
Vendor
ClamAV
Product
Cisco Modeling Labs
Classifications
CWE-88, T1059.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 22, 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 vectornetwork
Required privilegesauthenticated

What is affected?

ClamAV · Cisco Modeling Labsversion=n/a

Published CVSS scores

8.8Cisco Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
9.0NIST NVDAV:N/AC:L/Au:S/C:C/I:C/A:C

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-88Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
T1059.004Unix Shell

Public exploit references

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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