CVE-2021-1577Network attack vector

Unauthenticated arbitrary file access via upload endpoint

Published Aug 25, 2021 · Updated Nov 7, 2024

Improper access control in Cisco APIC allows remote attackers to read or write arbitrary files through an unauthenticated API endpoint. The endpoint accepts a crafted file upload without enforcing access control; Cisco has not disclosed its path or handler. Network reachability is sufficient, with no credentials or user interaction required and no reported availability impact.

CVSS severity9.1
Critical
EPSS probability1.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in Cisco APIC allows remote attackers to read or write arbitrary files through an unauthenticated API endpoint. The endpoint accepts a crafted file upload without enforcing access control; Cisco has not disclosed its path or handler. Network reachability is sufficient, with no credentials or user interaction required and no reported availability impact.

The record

CVE
CVE-2021-1577
Published
Aug 25, 2021
Updated
Nov 7, 2024
Vendor
ClamAV
Product
Cisco Application Policy Infrastructure Controller (APIC)
Classifications
CWE-284, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 25, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 7, 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 privilegesunauthenticated

What is affected?

ClamAV · Cisco Application Policy Infrastructure Controller (APIC)version=n/a

Published CVSS scores

9.1CiscoCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
6.4NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:N

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
T1190Exploit Public-Facing Application

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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