CVE-2023-34193Network attack vector

Authenticated code execution via ClientUploader file upload

Published Jul 6, 2023 · Updated Nov 19, 2024

Unrestricted file upload in Zimbra ZCS 8.8.15 allows remote authenticated users with administrative privileges to execute arbitrary code. The ClientUploader function accepts a dangerous file upload, but published records do not disclose the missing validation or subsequent file-handling path. Administrative access and an installed ClientUploader component are required; successful exploitation also exposes sensitive information on the server.

CVSS severity8.8
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

Unrestricted file upload in Zimbra ZCS 8.8.15 allows remote authenticated users with administrative privileges to execute arbitrary code. The ClientUploader function accepts a dangerous file upload, but published records do not disclose the missing validation or subsequent file-handling path. Administrative access and an installed ClientUploader component are required; successful exploitation also exposes sensitive information on the server.

The record

CVE
CVE-2023-34193
Published
Jul 6, 2023
Updated
Nov 19, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-434, T1190
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jul 6, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 19, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.8NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
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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