Critical Roundcube Vulnerability (CVE-2025-49113): Remote Code Execution Risk

 

Urgent security alert: Roundcube Webmail vulnerability (CVE-2025-49113) allows remote code execution via PHP object deserialization. Learn how to patch affected Ubuntu systems (16.04–25.04) and protect your email servers with enterprise-grade solutions.

Published: June 19, 2025 | Last Updated: June 21, 2025

Severity: High-Risk Remote Code Execution (RCE)

A critical vulnerability in Roundcube Webmail (CVE-2025-49113) exposes millions of email servers to remote code execution (RCE) attacks. This zero-day flaw, discovered in the _from URL parameter, enables attackers to inject malicious PHP objects via insecure deserialization.

Why This Matters for Enterprises:

• Affects all Ubuntu LTS releases (16.04 Xenial to 25.04 Plucky).

• Roundcube powers over 40% of open-source webmail deployments (Source: W3Techs).

• Exploits could lead to data breaches, ransomware, or credential theft.

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Patch Instructions for Ubuntu Systems

Affected Package Versions

Ubuntu Release	Package Name	Vulnerable Version	Patched Version
25.04 (Plucky)	roundcube-core	< 1.6.10+dfsg-1ubuntu0.1	1.6.10+dfsg-1ubuntu0.1
24.04 (Noble)	roundcube-plugins	< 1.6.6+dfsg-2ubuntu0.1	1.6.6+dfsg-2ubuntu0.1
22.04 (Jammy)	roundcube	< 1.5.0+dfsg.1-2ubuntu0.1~esm4	1.5.0+dfsg.1-2ubuntu0.1~esm4

How to Update

1. Terminal Command:

   bash

   sudo apt update && sudo apt upgrade roundcube*  

2. Verify Fixes:

   bash

   apt list --installed | grep roundcube  

For Legacy Systems: Ubuntu Pro (free for 5 machines) extends security patches for 10 years. Get Ubuntu Pro.

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Mitigation Strategies for Enterprise Security Teams

1. Immediate Actions:

   • Disable Roundcube if patching isn’t feasible.

   • Monitor logs for _from parameter tampering.

2. Long-Term Solutions:

   • Migrate to hardened email platforms (e.g., Zimbra, Open-Xchange).

   • Deploy Web Application Firewalls (WAFs) to filter exploit attempts.

Did You Know? 68% of webmail attacks target deserialization flaws (2024 Verizon DBIR).

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FAQs: Roundcube CVE-2025-49113

Q: Is my Ubuntu server vulnerable?

A: Yes, if running Roundcube versions listed above.

Q: What’s the exploit’s CVSS score?

A: 9.8 (Critical) due to low attack complexity and high impact.

Q: Are cloud email services safer?

A: Yes—providers like ProtonMail or Tutanota mitigate such risks.