CVE-2025-48743

Executive Summary

CVE-2025-48743 is a SQL injection vulnerability in the SIGB PMB (PhpMyBibli) application, a library management system developed by Pmb. The vulnerability exists in versions prior to 8.0.1.2 and allows an unauthenticated attacker to inject arbitrary SQL commands via the application's input parameters. With a CVSS score of 5.3 (Medium), the primary impact is confidentiality breach, as an attacker could extract sensitive database contents, including user credentials and library records. No public proof-of-concept (PoC) or exploit code has been released at this time, and the EPSS score is 0.0%, indicating a low probability of exploitation in the wild. However, given the nature of SQL injection and the lack of a patch for some deployments, immediate remediation is advised.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby ecosystems. It is a standalone PHP application (SIGB PMB) and does not involve package manager dependencies.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
• Base Score: 5.3 (Medium)
• Attack Vector: Network (AV:N) – exploitable remotely.
• Attack Complexity: Low (AC:L) – no special conditions required.
• Privileges Required: None (PR:N) – no authentication needed.
• User Interaction: None (UI:N) – no user action required.
• Scope: Unchanged (S:U) – vulnerability does not affect other components.
• Confidentiality Impact: Low (C:L) – limited data exposure possible.
• Integrity Impact: None (I:N) – data cannot be modified.
• Availability Impact: None (A:N) – service availability not affected.

Threat Level: Medium. While the CVSS score is moderate, the lack of authentication requirements and the potential for data exfiltration make this a significant risk for exposed instances.

Deep Dive & Mechanics

The vulnerability resides in the SIGB PMB application's handling of user-supplied input within SQL queries. The application fails to properly sanitize or parameterize input fields, allowing an attacker to inject arbitrary SQL statements. This is a classic SQL injection flaw (CWE-89). The injection point is likely in a search or authentication parameter, as these are common entry points in library management systems.

The attack flow:

1. An attacker sends a crafted HTTP request to a vulnerable endpoint (e.g., /pmb/opac_css/ or similar).
2. The request includes a malicious SQL payload in a parameter such as id, search, or user.
3. The application concatenates this input directly into a SQL query without proper escaping.
4. The database executes the attacker's SQL, potentially returning sensitive data or allowing further exploitation.

Example vulnerable code pattern (conceptual):

$query = "SELECT * FROM users WHERE id = " . $_GET['id'];
$result = mysqli_query($conn, $query);

The patched version (8.0.1.2) likely uses prepared statements or input validation to prevent injection.

Vulnerable vs. Patched Code

Vulnerable Code (Pre-8.0.1.2):

// Vulnerable: direct concatenation of user input
$id = $_GET['id'];
$sql = "SELECT * FROM livres WHERE id_livre = $id";
$result = mysqli_query($conn, $sql);

Patched Code (8.0.1.2+):

// Patched: using prepared statements
$id = $_GET['id'];
$stmt = $conn->prepare("SELECT * FROM livres WHERE id_livre = ?");
$stmt->bind_param("i", $id);
$stmt->execute();
$result = $stmt->get_result();

The key difference is the use of parameterized queries, which separate SQL logic from data, preventing injection.

Exploitation & Lab Setup

Red Team (Offensive)

Since no public exploit code is available, a manual SQL injection test can be performed:

1. Identify vulnerable endpoint: Use a web scanner or manual inspection to find parameters (e.g., id, search, isbn).
2. Test for injection: Submit a single quote (') and observe error messages or behavior changes.
3. Extract data: Use UNION-based or blind SQL injection techniques. Example payload:

   http://target/pmb/opac_css/?id=1 UNION SELECT 1,2,3,4,5,6,7,8,9,10--
   

4. Automate with sqlmap:

   sqlmap -u "http://target/pmb/opac_css/?id=1" --batch --dbs
   

Lab Setup:

• Download a vulnerable version (e.g., 8.0.1.1) from the official PMB repository.
• Install on a local LAMP/LEMP stack.
• Use a tool like Burp Suite or OWASP ZAP to intercept and modify requests.

Blue Team (Defensive)

Detection:

• Monitor web server logs for SQL injection patterns (e.g., ' OR '1'='1, UNION SELECT, --).
• Deploy a Web Application Firewall (WAF) with SQL injection signatures.
• Use database activity monitoring to detect anomalous queries.

Honeypot:

• Set up a decoy PMB instance to capture attacker behavior.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests containing SQL keywords in parameters: UNION, SELECT, OR, AND, --, #, '.
  • Unusual database error messages in HTTP responses (e.g., "You have an error in your SQL syntax").
• File IOCs:
  • Modified PHP files in the PMB directory (e.g., opac_css/ or admin/).
  • Suspicious log entries in /var/log/apache2/error.log or /var/log/mysql/error.log.
• System IOCs:
  • Unexpected database connections from external IPs.
  • New user accounts or elevated privileges in the PMB database.

Detection Engineering

YARA Rule

rule CVE_2025_48743_SQLi_PMB {
    meta:
        description = "Detects SQL injection attempts targeting SIGB PMB CVE-2025-48743"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-48743"
    strings:
        $sqli1 = /[?&](id|search|isbn|user)=.*['\"]\s*(OR|AND|UNION|SELECT|--|#)/i
        $sqli2 = /['\"]\s*(OR|AND)\s+['\"]\s*['\"]\s*=\s*['\"]/i
        $sqli3 = /UNION\s+SELECT\s+.*FROM/i
    condition:
        any of them
}

Sigma Rule

title: SQL Injection Attempt Against SIGB PMB
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects SQL injection patterns in HTTP requests to PMB endpoints
author: Valters IT
logsource:
    category: webserver
    product: apache
    service: accesslog
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains:
            - "' OR"
            - "' AND"
            - "UNION SELECT"
            - "--"
            - "1=1"
            - "1=2"
    condition: selection
falsepositives:
    - Legitimate use of special characters in search queries (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-48743 SQL Injection Attempt - SIGB PMB"; flow:to_server,established; content:"GET"; http_method; content:"/pmb/"; http_uri; pcre:"/(?:\?|&)(?:id|search|isbn|user)=[^&]*['\"]\s*(?:OR|AND|UNION|SELECT|--|#)/i"; classtype:web-application-attack; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Upgrade: Update SIGB PMB to version 8.0.1.2 or later. This is the only complete fix.
2. WAF Rules: Deploy virtual patching via a WAF to block SQL injection patterns.
3. Input Validation: If upgrade is not possible, implement input sanitization for all parameters (e.g., allow only alphanumeric characters for IDs).

Long-Term Measures:

• Conduct a code review to ensure all database queries use prepared statements.
• Implement least-privilege database accounts for the application.
• Enable detailed logging and monitoring for web and database servers.
• Regularly apply security patches from the vendor.

Workaround (if patching is delayed):

• Restrict network access to the PMB web interface (e.g., VPN or IP whitelisting).
• Disable unnecessary features that accept user input.

Valters IT