CVE-2020-12846Network attack vector

Authenticated code execution via retained avatar uploads

Published Jun 3, 2020 · Updated Aug 4, 2024

Unrestricted file upload in Zimbra Collaboration before 8.8.15 Patch 10 allows remote authenticated users to execute code. The /service/upload servlet accepts executable files submitted as contact avatars and retains them in /opt/zimbra/data/tmp/upload/ even after reporting a corrupt-file error. An authenticated mailbox account and the contact-avatar workflow are required; 9.x releases before 9.0.0 Patch 3 are also affected.

CVSS severity8.0
High
EPSS probability2.62%
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 Collaboration before 8.8.15 Patch 10 allows remote authenticated users to execute code. The /service/upload servlet accepts executable files submitted as contact avatars and retains them in /opt/zimbra/data/tmp/upload/ even after reporting a corrupt-file error. An authenticated mailbox account and the contact-avatar workflow are required; 9.x releases before 9.0.0 Patch 3 are also affected.

The record

CVE
CVE-2020-12846
Published
Jun 3, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-434, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 3, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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 privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.0NIST NVDAV:N/AC:M/Au:S/C:P/I:P/A:P
8.0NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/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 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 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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