Overview
CVE-2025-62691 describes a significant security vulnerability affecting the Security Point component of MaLion and MaLionCloud. This vulnerability is a stack-based buffer overflow that exists in the processing of HTTP headers. A remote, unauthenticated attacker can exploit this flaw to achieve arbitrary code execution with SYSTEM privileges on the affected system.
Technical Details
The vulnerability stems from insufficient bounds checking when handling HTTP headers within the Security Point component. By sending a specially crafted HTTP request containing an overly long header value, an attacker can overwrite data on the stack. This overwrite can potentially redirect execution flow to attacker-controlled code, leading to complete system compromise.
The specific location of the buffer overflow is within the HTTP header parsing routine. Detailed analysis of the MaLion/MaLionCloud code is required to pinpoint the exact function and affected header fields. Reversing the affected binaries will reveal the vulnerable code section.
Example of a potentially malicious HTTP header (illustrative):
GET / HTTP/1.1
Custom-Header: AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
Host: vulnerable.example.com
Note: The above is a simplified example. The actual exploit might require more complex crafted data to achieve reliable code execution.
CVSS Analysis
As per the provided information, the CVSS score and severity are currently marked as “N/A”. However, given the nature of a stack-based buffer overflow leading to SYSTEM privilege escalation, a high CVSS score (likely above 9.0) is expected. We will update this section when official CVSS information becomes available. Factors contributing to a high score include:
- Remote Attack Vector: The vulnerability is exploitable remotely, requiring no local access.
- No Authentication Required: An attacker does not need to authenticate to exploit the vulnerability.
- Complete Confidentiality, Integrity, and Availability Impact: Successful exploitation leads to full control of the system.
Possible Impact
Successful exploitation of CVE-2025-62691 can have severe consequences:
- Complete System Compromise: An attacker gains full control of the affected system with SYSTEM privileges.
- Data Breach: Sensitive data stored on the system can be accessed and exfiltrated.
- Malware Installation: The attacker can install malware, including ransomware, to further compromise the system and network.
- Lateral Movement: The compromised system can be used as a stepping stone to attack other systems on the network.
- Denial of Service: The attacker could crash the system or disrupt its normal operation.
Mitigation and Patch Steps
The primary mitigation strategy is to apply the patch provided by Intercom. Immediate action is required to protect systems from potential exploitation.
- Apply the Official Patch: Download and install the latest version of MaLion/MaLionCloud from the vendor’s website (https://www.intercom.co.jp/information/2025/1125.html). Refer to the vendor’s instructions for detailed patching procedures.
- Monitor Network Traffic: Implement intrusion detection and prevention systems (IDS/IPS) to monitor network traffic for suspicious HTTP requests targeting MaLion/MaLionCloud. Look for abnormally long HTTP header values.
- Web Application Firewall (WAF): If feasible, deploy a Web Application Firewall (WAF) to filter out malicious HTTP requests before they reach the vulnerable application. Configure the WAF to block requests with excessively long header values.
- Review Security Logs: Regularly review security logs for any signs of exploitation attempts.
