CVE-2025-9559

Executive Summary

CVE-2025-9559 is an Insecure Direct Object Reference (IDOR) vulnerability affecting Pega Platform versions 8.7.5 through Infinity 24.2.2. This flaw exists within a user interface component, allowing an authenticated attacker to read unauthorized data by manipulating object references. The vulnerability has a CVSS score of 6.5 (Medium), with a low attack complexity and no user interaction required. No public proof-of-concept (PoC) or exploit code has been released, and the vendor has not yet provided a patch. The EPSS score is 0.0%, indicating a very low probability of exploitation in the wild at this time.

CVSS Breakdown & Threat Level

• CVSS Score: 6.5 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
• Attack Vector (AV): Network (N) – Exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): Low (L) – Attacker needs valid credentials.
• User Interaction (UI): None (N) – No victim action needed.
• Scope (S): Unchanged (U) – Impact confined to the vulnerable component.
• Confidentiality (C): High (H) – Complete data read access.
• Integrity (I): None (N) – No data modification possible.
• Availability (A): None (N) – No denial of service.

Threat Level: Medium. While the confidentiality impact is high, the requirement for authentication and the lack of public exploits reduce immediate risk. However, the absence of a patch makes this a persistent threat for unpatched systems.

Deep Dive & Mechanics

The vulnerability is an Insecure Direct Object Reference (IDOR) in a Pega Platform UI component. IDOR occurs when an application exposes a direct reference to an internal object (e.g., a database key, file path, or user ID) without proper authorization checks. In this case, an authenticated user can manipulate a parameter (likely a numeric or string identifier) in a UI request to access data belonging to other users or entities.

Technical Walkthrough:

1. An authenticated user interacts with a Pega UI component that fetches data based on a user-supplied identifier (e.g., ?userID=12345).
2. The application fails to verify that the requesting user has permission to access the object associated with that identifier.
3. By changing the identifier (e.g., to 12346), the attacker can read data from other users or sensitive system objects.
4. The vulnerability is limited to read operations; no write or delete capabilities are exposed.

Root Cause: The UI component does not enforce proper access control checks before returning data. This is a classic authorization bypass, often due to missing or insufficient server-side validation of user permissions.

Vulnerable vs. Patched Code

Since no patch is available, a generic example of vulnerable vs. patched code is provided.

Vulnerable Code (Java/Pega Rule):

// Vulnerable: No authorization check
public DataPage getData(String objectID) {
    return dataService.fetchObject(objectID);
}

Patched Code (Conceptual):

// Patched: Authorization check added
public DataPage getData(String objectID, User currentUser) {
    if (!authorizationService.canRead(currentUser, objectID)) {
        throw new AccessDeniedException("Unauthorized access");
    }
    return dataService.fetchObject(objectID);
}

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• Valid credentials for a Pega Platform instance (version 8.7.5 to 24.2.2).
• Network access to the Pega UI.

Exploitation Steps:

1. Log in to the Pega Platform.
2. Identify a UI component that loads data based on a user-controlled parameter (e.g., a user profile page with ?userID=12345).
3. Intercept the request using a proxy (e.g., Burp Suite).
4. Modify the parameter value (e.g., change userID=12345 to userID=12346).
5. Forward the request and observe the response for unauthorized data.

Example Request:

GET /prweb/PRServlet/UserProfile?userID=12345 HTTP/1.1
Host: target-pega-instance.com
Cookie: JSESSIONID=abc123

Modified Request:

GET /prweb/PRServlet/UserProfile?userID=12346 HTTP/1.1
Host: target-pega-instance.com
Cookie: JSESSIONID=abc123

Blue Team (Defensive)

Detection:

• Monitor for anomalous access patterns to UI components, especially sequential or brute-force attempts on object IDs.
• Alert on multiple failed authorization attempts (HTTP 403) followed by successful reads of different objects.

Mitigation:

• Implement strict server-side authorization checks for all data access.
• Use indirect object references (e.g., random tokens) instead of direct database keys.
• Apply the principle of least privilege to all user roles.

Indicators of Compromise (IOCs)

• Network: HTTP requests with sequential or predictable object IDs in parameters (e.g., ?userID=12345, ?userID=12346).
• Logs: Pega access logs showing repeated access to different object IDs by the same user within a short timeframe.
• System: Unusual data access patterns in database query logs (e.g., queries for objects outside the user's scope).

Detection Engineering

YARA Rule

rule CVE_2025_9559_IDOR_Detection {
    meta:
        description = "Detects potential IDOR exploitation attempts against Pega Platform"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-9559"
    strings:
        $param1 = "userID=" ascii wide nocase
        $param2 = "objectID=" ascii wide nocase
        $param3 = "recordID=" ascii wide nocase
    condition:
        any of ($param*) and #param1 > 5
}

Sigma Rule

title: Pega Platform IDOR Exploitation Attempt
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects multiple requests with different object IDs from the same user, indicating potential IDOR scanning.
author: Valters IT
logsource:
    category: web
    product: pega
detection:
    selection:
        http_method: GET
        url|contains: 
            - 'userID='
            - 'objectID='
            - 'recordID='
    condition: selection | count() by src_ip > 10 within 5m
falsepositives:
    - Legitimate bulk data operations
level: medium

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-9559 Pega Platform IDOR Attempt";
    flow:to_server,established;
    content:"GET"; http_method;
    content:"userID="; http_uri;
    pcre:"/userID=\d{5,}/";
    threshold: type both, track by_src, count 10, seconds 300;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

1. Isolate affected systems if possible, or restrict network access to trusted users only.
2. Monitor logs for suspicious IDOR patterns and block offending IPs.
3. Apply virtual patching via WAF rules to block requests with sequential object IDs.

Long-term Fix:

• Apply the official patch from Pegasystems once released.
• Implement robust authorization checks in all UI components.
• Conduct a security audit of all data access points.

Workarounds:

• Disable the vulnerable UI component if it is not critical.
• Use indirect object references (e.g., GUIDs) instead of sequential IDs.

Valters IT