Number: AL25-007
Date: June 11, 2025
Audience
This Alert is intended for IT professionals and managers of notified organizations.
Purpose
An Alert is used to raise awareness of a recently identified cyber threat that may impact cyber information assets, and to provide additional detection and mitigation advice to recipients. The Canadian Centre for Cyber Security ("Cyber Centre") is also available to provide additional assistance regarding the content of this Alert to recipients as requested.
Details
On June 1, 2025, Roundcube released a security bulletin for a critical vulnerability affecting Webmail. The issue is described as a Post-Auth RCE via PHP Object Deserialization vulnerability (CVE-2025-49113)Footnote 1. The versions of Roundcube products affected areFootnote 2:
- Webmail – versions prior to 1.5.10
- Webmail – versions prior to 1.6.11
In response to this vulnerability, the Cyber Centre released AV25-309 on June 2, 2025Footnote 3.
While the Cyber Centre has not received any reports of exploitation, the existence of a proof of concept (POC) significantly raises the likeness of abuse by malicious actors. The existence of a published POC makes it imperative to take action to assess and mitigate this vulnerability.
The Cyber Centre is aware that exploitation of CVE-2024-42009 has been used to obtain valid credentials, which could lead to exploitation of CVE-2025-49113. CISA added CVE-2024-42009 to their Known Exploited Vulnerabilities (KEV) catalogFootnote 4Footnote 5on June 9, 2025.
Suggested actions
The Cyber Centre strongly recommends that organizations update to Roundcube Webmail versions 1.5.10+ or 1.6.11+Footnote 2, which would mitigate issues reported by both CVEs mentioned here (CVE-2024-42009 and CVE-2025-49113).
The Cyber Centre recommends that organizations:
- Assess the installation of Roundcube Webmail.
- Apply updates to Roundcube Webmail without delay.
- Monitor affected systems for signs of exploitation.
- Monitor for brute-force attempts and if possible, implement rate limitation techniques.
In addition, the Cyber Centre strongly recommends that organizations review and implement the Cyber Centre’s Top 10 IT Security ActionsFootnote 6 with an emphasis on the following strategies:
If activity matching the content of this alert is discovered, recipients are encouraged to report via the My Cyber Portal, or email contact@cyber.gc.ca.