CVE-2023-20197Network attack vector

Service interruption via HFS+ decompression loop

Published Aug 16, 2023 · Updated Aug 2, 2024

Affected Cisco Secure Endpoint connectors allow remote attackers to interrupt scanning via a crafted HFS+ filesystem image. The ClamAV HFS+ parser incorrectly checks decompression completion, allowing a malformed image to trap the scanning process in a loop. No authentication or user interaction is required when the image reaches scanning; Windows services can remain unresponsive and consume CPU, while Linux and macOS connectors recover on their own.

CVSS severity7.5
High
EPSS probability1.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Affected Cisco Secure Endpoint connectors allow remote attackers to interrupt scanning via a crafted HFS+ filesystem image. The ClamAV HFS+ parser incorrectly checks decompression completion, allowing a malformed image to trap the scanning process in a loop. No authentication or user interaction is required when the image reaches scanning; Windows services can remain unresponsive and consume CPU, while Linux and macOS connectors recover on their own.

The record

CVE
CVE-2023-20197
Published
Aug 16, 2023
Updated
Aug 2, 2024
Vendor
ClamAV
Product
Cisco Secure Endpoint Private Cloud Console
Classifications
CWE-835, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 16, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 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 Secure Endpoint Private Cloud Consoleversion=N/A
ClamAV · Cisco Secure Endpointversion=1.10.0; version=1.10.1; version=1.10.2; version=1.11.0; version=1.12.0; version=1.12.1; version=1.12.2; version=1.12.3; version=1.12.4; version=1.12.5; version=1.12.6; version=1.12.7; version=1.13.0; version=1.13.1; version=1.13.2; version=1.14.0; version=1.6.0; version=1.7.0; version=1.8.0; version=1.8.1; version=1.8.4; version=1.9.0; version=1.9.1; version=6.0.7; version=6.0.9; version=6.1.5; version=6.1.7; version=6.1.9; version=6.2.1; version=6.2.19; version=6.2.5; version=6.2.9; version=6.3.1; version=6.3.3; version=6.3.5; version=6.3.7; version=7.0.5; version=7.1.1; version=7.1.5; version=7.2.11; version=7.2.13; version=7.2.3; version=7.2.5; version=7.2.7; version=7.3.3; version=7.3.5; version=8.1.5

Published CVSS scores

5.3CiscoCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
7.5CiscoCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499Endpoint Denial of Service

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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