CVE-2025-53008

Executive Summary

CVE-2025-53008 is a medium-severity vulnerability in GLPI (Gestionnaire Libre de Parc Informatique), an open-source IT asset management and helpdesk software. A connected (authenticated) user can craft a malicious payload to steal mail receiver credentials. This is a credential theft vulnerability that could lead to further compromise of email infrastructure. The vulnerability affects GLPI versions 9.3.1 through 10.0.18. The patch is available in version 10.0.19.

Supply Chain & Package Security

GLPI is a PHP-based application distributed as a ZIP archive or via Composer. The vulnerability exists in the core application code, not in a third-party package. However, the compromise of mail receiver credentials could impact the supply chain if the mail server is used for automated deployments or notifications.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) - The attack is performed over the network.
• Attack Complexity (AC): Low (L) - No special conditions are required.
• Privileges Required (PR): Low (L) - The attacker must be an authenticated user.
• User Interaction (UI): None (N) - No user interaction is required.
• Scope (S): Unchanged (U) - The vulnerability does not affect other components.
• Confidentiality (C): High (H) - Mail receiver credentials are fully disclosed.
• Integrity (I): None (N) - No data integrity impact.
• Availability (A): None (N) - No availability impact.

Threat Level: Medium. The vulnerability requires authentication, but the impact is high due to credential theft.

Deep Dive & Mechanics

The vulnerability lies in how GLPI handles mail receiver configuration. A connected user can inject a malicious payload into the mail receiver configuration fields. When the configuration is saved or processed, the payload is executed, allowing the attacker to exfiltrate the mail receiver credentials (username and password).

The exact mechanism is not publicly disclosed, but it likely involves a lack of input sanitization or improper handling of serialized data. The attacker could use a technique such as PHP object injection or SQL injection to extract the credentials from the database or configuration files.

Vulnerable vs. Patched Code

The vulnerable code is in the mail receiver configuration module. The patch in version 10.0.19 likely includes input validation and sanitization to prevent the injection of malicious payloads.

Vulnerable Code (Conceptual):

// Vulnerable: No input sanitization
$mailReceiverConfig = $_POST['mail_receiver_config'];
saveConfig($mailReceiverConfig);

Patched Code (Conceptual):

// Patched: Input sanitization and validation
$mailReceiverConfig = sanitizeInput($_POST['mail_receiver_config']);
if (validateConfig($mailReceiverConfig)) {
    saveConfig($mailReceiverConfig);
}

Exploitation & Lab Setup

Red Team

1. Setup: Deploy a vulnerable GLPI instance (version 10.0.18 or earlier) with a configured mail receiver.
2. Authentication: Log in as a standard user.
3. Payload Crafting: Craft a malicious payload that, when processed, will exfiltrate the mail receiver credentials. This could be a PHP object injection payload or a SQL injection payload.
4. Injection: Inject the payload into the mail receiver configuration fields (e.g., via a POST request to the configuration endpoint).
5. Exfiltration: The payload executes and sends the credentials to an attacker-controlled server.

Example Payload (Conceptual):

// PHP Object Injection payload
O:10:"MailReceiver":2:{s:4:"user";s:5:"admin";s:4:"pass";s:8:"password";}

Blue Team

1. Detection: Monitor for unusual POST requests to mail receiver configuration endpoints.
2. Logging: Enable detailed logging of all configuration changes.
3. Network Monitoring: Monitor for outbound connections to unknown IP addresses from the GLPI server.
4. Honeypot: Deploy a fake mail receiver configuration to detect exploitation attempts.

Indicators of Compromise (IOCs)

• Network: Outbound connections to unknown IP addresses on port 25, 587, or 465.
• File: Unusual entries in GLPI configuration files (e.g., config/config_db.php).
• Log: Suspicious entries in GLPI logs indicating configuration changes by unauthorized users.
• Process: Unexpected PHP processes executing on the server.

Detection Engineering

YARA Rule

rule CVE_2025_53008_GLPI_Mail_Receiver_Exploit {
    meta:
        description = "Detects malicious payloads targeting CVE-2025-53008 in GLPI"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-53008"
    strings:
        $payload1 = "mail_receiver_config" ascii wide nocase
        $payload2 = "O:10:\"MailReceiver\"" ascii wide nocase
        $payload3 = "s:4:\"user\"" ascii wide nocase
        $payload4 = "s:4:\"pass\"" ascii wide nocase
    condition:
        any of ($payload*) and #payload1 > 0
}

Sigma Rule

title: CVE-2025-53008 GLPI Mail Receiver Credential Theft
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects exploitation attempts of CVE-2025-53008 in GLPI
author: Valters IT
date: 2025-04-10
references:
    - https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-53008
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'mail_receiver_config'
    condition: selection
falsepositives:
    - Legitimate configuration changes by administrators
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-53008 GLPI Mail Receiver Credential Theft"; flow:to_server,established; content:"POST"; http_method; content:"mail_receiver_config"; http_uri; content:"O:10:\"MailReceiver\""; http_client_body; classtype:attempted-user; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate: Upgrade to GLPI version 10.0.19 or later.
2. Workaround: If immediate upgrade is not possible, restrict access to the mail receiver configuration page to only trusted administrators.
3. Compensating Controls: Implement Web Application Firewall (WAF) rules to block malicious payloads.
4. Monitoring: Enable detailed logging and monitor for suspicious activity.
5. Credential Rotation: Rotate all mail receiver credentials immediately after patching.

Valters IT