Full Report
Zimbra has rolled out fixes to address multiple critical security issues, including a command injection flaw in the Simple Network Management Protocol (SNMP) monitoring component. As many as nine security vulnerabilities have been patched in Zimbra 10.1.20. Topping the list is a command injection vulnerability in the SNMP monitoring component when SNMP notifications are enabled. Also patched
Analysis Summary
# Vulnerability: Zimbra SNMP Command Injection and Multiple XSS Critical Flaws
## CVE Details
- **CVE ID:** CVE-2026-50055 (Mail forwarding restriction bypass); Others not specifically listed in source (See vendor advisory).
- **CVSS Score:** Not explicitly provided, but categorized as **Critical**.
- **CWE:**
- CWE-77 (Command Injection)
- CWE-79 (Cross-Site Scripting)
## Affected Systems
- **Products:** Zimbra Collaboration Suite
- **Versions:** Versions prior to 10.1.20
- **Configurations:**
- The Command Injection vulnerability requires **SNMP notifications** to be enabled.
- The XSS vulnerabilities specifically affect the **Classic Web Client**.
## Vulnerability Description
Zimbra has patched nine vulnerabilities in total. The primary flaw is a **Command Injection** vulnerability within the SNMP monitoring component. This occurs when SNMP notifications are active, allowing an attacker to inject and execute arbitrary commands.
Additionally, four **Cross-Site Scripting (XSS)** vulnerabilities were addressed in the Classic Web Client. These flaws relate to how the system renders "crafted fields," malicious attachment filenames, and specific attachment types, allowing for the execution of malicious scripts in the context of the user's session.
## Exploitation
- **Status:** Not currently exploited in the wild; No public PoC mentioned for the SNMP flaw.
- **Complexity:** Medium (dependent on specific configurations like SNMP being enabled).
- **Attack Vector:** Network / Web-based.
## Impact
- **Confidentiality:** Critical (Full access to email data and system credentials).
- **Integrity:** Critical (Ability to execute system commands and modify web content).
- **Availability:** High (Potential for system takeover or service disruption).
## Remediation
### Patches
- **Upgrade to Zimbra 10.1.20** or later. This release addresses all nine identified security issues.
### Workarounds
- **Disable SNMP Notifications:** If an immediate patch is not possible and SNMP monitoring is not required, disabling SNMP notifications may mitigate the command injection vector.
- **Use Modern Web Client:** Avoiding the "Classic Web Client" may reduce exposure to the reported XSS vulnerabilities.
## Detection
- **Indicators of compromise:** Monitor for unusual child processes originating from SNMP-related services or unexpected outbound network connections from the Zimbra server.
- **Detection methods and tools:** Audit web server logs for suspicious script tags or encoded payloads in requests directed at the Classic Web Client interface.
## References
- **Vendor Advisory:** [https[:]//blog.zimbra.com/2026/07/patch-release-update-zimbra-10-1-20/](https[:]//blog.zimbra.com/2026/07/patch-release-update-zimbra-10-1-20/)
- **Release Notes:** [https[:]//wiki.zimbra.com/wiki/Zimbra_Releases/10.1.20](https[:]//wiki.zimbra.com/wiki/Zimbra_Releases/10.1.20)
- **Source Article:** [https[:]//thehackernews.com/2026/07/zimbra-patches-critical-snmp-command.html](https[:]//thehackernews.com/2026/07/zimbra-patches-critical-snmp-command.html)