Horizon Alert
Summary of the vulnerability and why it matters
Craft CMS allows unauthenticated users to introduce arbitrary values, such as PHP code, into session files stored on the server. This occurs because the system does not properly sanitize parameters in return URLs, which are then used to name session files. This vulnerability could potentially lead to the execution of unintended code.
- Vulnerable component: Craft CMS session files
- Core weakness: Unsanitized return URL parameters
- Main business impact: Potential for arbitrary code execution
Attack Path
How an attacker could exploit the issue
An unauthenticated user can introduce arbitrary values, such as PHP code, into session files on the server by manipulating return URL parameters. This occurs because Craft CMS does not sanitize these parameters when redirecting requests that require authentication. The session files are created in a predictable location on the server, allowing the malicious input to be stored.
- Exposure condition: Unauthenticated access to Craft CMS.
- Attacker starting point: Network.
- Trigger and result: Inject code into session files.
Live Threat
Current exploitation, exposure, and threat context
The Craft CMS vulnerability presents a significant risk to organizations utilizing the platform. Attackers can potentially inject arbitrary code into session files, leading to unauthorized access and execution on the server. This could result in data compromise and system disruption, impacting business operations. Organizations should consider this a high-priority issue.
- Likely attacker skill level: Low
- Required access or conditions: None
- Business risk or urgency: High
Priority actions
Operational Fix
Recommended remediation, mitigation, and detection steps
The organization should address an unauthenticated user's ability to inject arbitrary code into session files on the server. This vulnerability could potentially lead to code execution, impacting system integrity and business operations. The known exploited vulnerabilities catalog lists this issue, indicating a potential for active exploitation by attackers.
- Find all Craft CMS assets.
- Reduce exposure or isolate affected systems.
- Apply vendor fixes and validate.
- Monitor for related activities.
