What’s Vulnerable › Vulnerabilities

CVE-2020-12846

• Severity: high (CVSS 8.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-06-03 · updated 2026-06-17
• Weakness: CWE-434

Description

Zimbra before 8.8.15 Patch 10 and 9.x before 9.0.0 Patch 3 allows remote code execution via an avatar file. There is potential abuse of /service/upload servlet in the webmail subsystem. A user can upload executable files (exe,sh,bat,jar) in the Contact section of the mailbox as an avatar image for a contact. A user will receive a "Corrupt File" error, but the file is still uploaded and stored locally in /opt/zimbra/data/tmp/upload/, leaving it open to possible remote execution.

Affected products

• Zimbra Collaboration: before 8.8.15; 8.8.15, 8.8.15-p1, 8.8.15-p2, 8.8.15-p3, 8.8.15-p4, 8.8.15-p5 (+7) — fixed in 8.8.15

How to fix

Upgrade to a fixed version: Zimbra Collaboration 8.8.15. Check the vendor advisory for mitigations.

References

• https://wiki.zimbra.com/wiki/Security_Center
• https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P3
• https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories
• https://wiki.zimbra.com/wiki/Security_Center
• https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P3
• https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories

Get alerted when CVE-2020-12846 or the next vulnerability affects your stack