Horizon Alert
Summary of the vulnerability and why it matters
This security flaw in TYPO3 allows an unauthenticated attacker to execute code remotely on the server. The issue stems from how the extension handles user-provided cookie data, which is then passed to a vulnerable PHP function without proper checks. This could lead to a complete compromise of the server if the plugin is configured in a specific way.
- Attackers can gain control of the server.
- This affects TYPO3 instances with specific configurations.
Attack Path
How an attacker could exploit the issue
A remote attacker can exploit this vulnerability by sending a specially crafted cookie to a TYPO3 server. If the vulnerable extension is configured to use "Persistent Mode: Static", the attacker's payload can trigger PHP Object Injection, allowing them to execute arbitrary code on the server. This bypasses authentication and requires no user interaction.
- Unauthenticated remote attacker.
- Targets TYPO3 server.
- Requires specific plugin configuration.
Live Threat
Current exploitation, exposure, and threat context
This vulnerability offers a direct path to Remote Code Execution on TYPO3 servers, a common target for attackers. The ability for an unauthenticated attacker to leverage this through a crafted cookie, especially if the plugin is configured for static mode, presents a significant risk. While the specific configuration requirement might slightly limit immediate widespread exploitation, the severity of the outcome makes it a prime candidate for targeted attacks or inclusion in exploit kits.
- Unauthenticated RCE is highly desirable.
- Public exploit code is not yet observed.
- Recent advisory publication.
Priority actions
Operational Fix
Recommended remediation, mitigation, and detection steps
Prioritize immediate investigation of TYPO3 logs for signs of attempted exploitation of the PHP Object Injection vulnerability in the extension. If exploitation is detected or the extension is confirmed to be configured with "Persistent Mode: Static," isolate or take affected services offline until a patch can be applied.
- Review extension configuration for "Persistent Mode: Static."
- Block unauthenticated requests with suspicious serialized payloads.
- Monitor for outbound network connections from TYPO3 servers.
