CVE-2023-20116Network attack vector

Service interruption via infinite loop in AXL

Published Jun 28, 2023 · Updated Aug 2, 2024

Denial of service in Cisco Unified Communications Manager allows remote authenticated users to interrupt service through crafted HTTP input. Insufficient validation of Self Care Portal input lets crafted HTTP data drive AXL API processing into an infinite loop. A valid low-privilege account and user interaction are required, and the loop interrupts availability without reading or altering data.

CVSS severity6.8
Medium
EPSS probability0.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Cisco Unified Communications Manager allows remote authenticated users to interrupt service through crafted HTTP input. Insufficient validation of Self Care Portal input lets crafted HTTP data drive AXL API processing into an infinite loop. A valid low-privilege account and user interaction are required, and the loop interrupts availability without reading or altering data.

The record

CVE
CVE-2023-20116
Published
Jun 28, 2023
Updated
Aug 2, 2024
Vendor
ClamAV
Product
Cisco Unified Communications Manager
Classifications
CWE-835, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 28, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=12.0(1)SU1
  2. Affected versionversion=12.0(1)SU2
  3. Affected versionversion=12.0(1)SU3
  4. Affected versionversion=12.0(1)SU4
  5. Affected versionversion=12.0(1)SU5
  6. Affected versionversion=12.5(1)
  7. Affected versionversion=12.5(1)SU1
  8. Affected versionversion=12.5(1)SU2
  9. Affected versionversion=12.5(1)SU3
  10. Affected versionversion=12.5(1)SU4
  11. Affected versionversion=12.5(1)SU5
  12. Affected versionversion=12.5(1)SU6
  13. Affected versionversion=12.5(1)SU7
  14. Affected versionversion=12.5(1)SU7a
  15. Affected versionversion=14
  16. Affected versionversion=14SU1
  17. Affected versionversion=14SU2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

ClamAV · Cisco Unified Communications Managerversion=12.0(1)SU1; version=12.0(1)SU2; version=12.0(1)SU3; version=12.0(1)SU4; version=12.0(1)SU5; version=12.5(1); version=12.5(1)SU1; version=12.5(1)SU2; version=12.5(1)SU3; version=12.5(1)SU4; version=12.5(1)SU5; version=12.5(1)SU6; version=12.5(1)SU7; version=12.5(1)SU7a; version=14; version=14SU1; version=14SU2

Published CVSS scores

6.8Cisco Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:N/A:H/E:X/RL:X/RC:X
5.7NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:L/UI:R/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
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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