Number: AL24-013
Date: December 16, 2024
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 November 26 2024, the Apache Software Foundation released a security bulletin for CVE-2024-53677, a critical vulnerability affecting both end-of-life and current versions of Apache Struts 2Footnote 1Footnote 3.
The vulnerability has been assigned a CVSS severity rating of 9.5 out of 10Footnote 4.
A malicious actor can exploit this vulnerability to traverse system paths, upload malicious files, and perform remote code executionFootnote 1Footnote 2.
The versions of Apache Struts 2 affected by this vulnerability are:
- 2.0.0 to 2.3.37
- 2.5.0 to 2.5.33
- 6.0.0 to 6.3.0.2
Note that only applications that use FileUploadInterceptor are vulnerableFootnote 1. FileUploadInterceptor is deprecated as of Struts 6.4.0.Footnote 2
Apache Struts 2 is widely adopted in both the private and public sectors and past vulnerabilities have had significant business impact.
The Cyber Centre is aware that a proof of concept (POC) exploit is available for this CVE. The existence of a published POC makes it imperative to take action to assess and mitigate this vulnerability.
Recommendations
The Cyber Centre strongly recommends that organizations patch the affected Apache Struts 2 systems to versions 6.4.0 or greater and remove the deprecated FileUploadInterceptor. Similar functionality is supported by ActionFileUploadInterceptor.Footnote 2
Apache Struts versions 2.0.0 to 2.3.37 are vulnerable but are no longer supported and therefore present significant business risk. Impacted organizations should replace unsupported products with supported versions.Footnote 1
The Cyber Centre recommends that organizations:
- Assess the inventory of Apache Struts on their hosts and monitor for signs of exploitation,
- Apply software patches to Apache Struts 2 without delay.
In addition, the Cyber Centre strongly recommends that organizations review and implement the Cyber Centre’s Top 10 IT Security Actions Footnote 5 with an emphasis on the following strategies:
- Consolidate, monitor, and defend Internet gateways
- Patch operating systems and applications
- Isolate web-facing applications
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.
Partner reporting
ASCS – Critical security vulnerability affecting Apache Struts2 below 6.4.0
About The Cyber Centre
The Canadian Centre for Cyber Security (Cyber Centre) operates as part of the Communications Security Establishment. We are Canada's national authority on cyber security, and we lead the government's response to cyber security events. As Canada's national computer security incident response team, the Cyber Centre works in close collaboration with government departments, critical infrastructure, Canadian businesses, and international partners to prepare for, respond to, mitigate, and recover from cyber events. We do this by providing authoritative advice and support and coordinating information sharing and incident response. The Cyber Centre is outward-facing, welcoming partnerships that help build a stronger, more resilient cyber space in Canada.