External risk intelligence

Roundcube Webmail Command Injection Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2024-37385

Roundcube Webmail is a public-facing email client application designed to be accessed over the internet by users to read and manage email. As a webmail interface, it is intended to be reachable via public network endpoints to facilitate remote access for users, making its attack surface inherently public-facing by design.

Command Injection

Roundcube Webmail

before 1.5.71.6.0 to before 1.6.7

Halo Surface Signal: 5 out of 5 — more likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability has been identified in Roundcube Webmail, a widely used email client. This issue could allow attackers to execute commands on affected systems, potentially leading to significant compromise. The main concern at this time is to confirm if our environment is running the affected software and assess any potential exposure.

Allows attackers to run commands remotely.
Matters for organizations using Roundcube Webmail.
Confirm if Roundcube Webmail is in use.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this vulnerability by sending a specially crafted request to an unauthenticated Roundcube Webmail instance. This request targets a feature that processes image conversion paths, allowing the attacker to inject operating system commands. Successful exploitation could lead to significant compromise of the underlying server.

No authentication required.
Image processing with crafted path.
Full server compromise possible.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow an unauthenticated attacker to execute arbitrary commands on the server when specific conditions related to image conversion are met, potentially impacting system integrity and data confidentiality.

System commands execution.
Via specially crafted requests.
Server compromise and data exposure.

Operational Fix

Recommended remediation, mitigation, and detection steps

Application owners responsible for Roundcube Webmail deployments should prioritize identifying all instances, confirming their reachability and business criticality. Once ownership is confirmed, a risk-based remediation plan can be developed, potentially involving coordination with vendors and planning for maintenance windows.

Application owners own the issue.
Verify Roundcube instance reachability.
Plan remediation based on risk.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is Roundcube Webmail?

Roundcube Webmail is a popular, open-source email client that provides a web-based interface for users to access, read, and manage their email accounts. It is designed to run on a server, acting as a bridge between the user's browser and the mail server, allowing for remote communication and organization of messages.

What does CWE-77 mean for CVE-2024-37385?

CWE-77 refers to Command Injection. In the context of CVE-2024-37385, this means the software does not properly filter user-supplied input before passing it to system-level functions. By exploiting this flaw, an attacker can trick the server into running unauthorized commands on the underlying Windows operating system, essentially gaining the ability to execute their own instructions.

How is this command injection triggered?

The vulnerability is triggered by sending a specially crafted request to an affected Roundcube instance that influences how the software handles image conversion paths. Simply having the software installed does not trigger the bug; the attacker must specifically target the image processing features. Requests that do not interact with these specific path-handling components will not initiate the malicious command execution.

Is my server at risk according to Halo Surface Signal?

Halo Surface Signal notes that Roundcube Webmail is inherently public-facing because it is designed to be accessed over the internet for remote email management. Because it is intended to be reachable via public network endpoints, any instance of the application accessible from the internet possesses an expanded attack surface that requires immediate attention.

What should I do if I run Roundcube Webmail?

Your first step is to identify all deployed instances of Roundcube in your environment and determine their version numbers. If you are running a version earlier than 1.5.7 or 1.6.7 on Windows, prioritize these for updates. Confirm which instances are reachable from the internet, as these are the highest priority for remediation, and coordinate with your team to plan a maintenance window for applying the necessary vendor patches.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.