Description
An SMTP command injection vulnerability in the data-source testing functionality of Zimbra Collaboration Suite (ZCS) allows an ordinary authenticated user with account options enabled to inject CR/LF into the emailAddress inserted into an SMTP envelope command by a JSON SOAP request. After a successful preliminary POP3 or IMAP login, Zimbra sends the injected commands to the selected SMTP service. If that service accepts the pipelined transaction, the attacker can submit mail with attacker-selected recipients, headers and body content without victim interaction. The vulnerable command-construction path is present in ZCS 10.1.16 and 10.1.20.
Affected products
synacor: zimbra collaboration suite
References2
- wiki.zimbra.com/wiki/Zimbra_Security_Advisories Vendor Advisory
- www.rapid7.com/blog/post/ve-breaking-zimbra-identity-boundaries… Not Applicable
Metrics
- CVSS 3.1
-
4.3
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N - EPSS — exploit probability
- 1% percentile: 55 · as of 8 November 2026
- CWE
- CWE-93
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