CVE-2025-47933: Argo CD XSS Vulnerability

CVE-2025-47933 Overview

CVE-2025-47933 is a Cross-Site Scripting (XSS) vulnerability affecting Argo CD, a popular declarative GitOps continuous delivery tool for Kubernetes. The vulnerability exists due to improper filtering of URL protocols in the repository page, allowing attackers with permission to edit repositories to inject malicious scripts and perform arbitrary actions on behalf of authenticated users via the API.

Critical Impact

Authenticated attackers with repository edit permissions can execute arbitrary JavaScript in the context of victim users' sessions, enabling session hijacking, data theft, and unauthorized actions within the Argo CD deployment pipeline.

Affected Products

• Argo CD versions prior to 2.13.8
• Argo CD versions prior to 2.14.13
• Argo CD versions prior to 3.0.4

Discovery Timeline

• 2025-05-29 - CVE-2025-47933 published to NVD
• 2025-08-27 - Last updated in NVD database

Technical Details for CVE-2025-47933

Vulnerability Analysis

This vulnerability stems from insufficient input validation in the Argo CD web UI's repository configuration page. The application fails to properly filter and sanitize URL protocol schemes when processing repository URLs, creating an avenue for stored XSS attacks. An attacker who has been granted repository edit permissions can craft a malicious URL containing JavaScript payloads that execute when other users view the repository configuration.

The XSS vulnerability enables attackers to hijack user sessions, steal authentication tokens, modify Kubernetes deployment configurations, and perform any action the victim is authorized to execute within Argo CD. Given Argo CD's role in managing Kubernetes deployments, successful exploitation could lead to supply chain attacks affecting the entire application delivery pipeline.

Root Cause

The root cause is improper URL protocol validation in the repository page component. The application accepts and renders URL values without verifying they conform to safe protocol schemes (such as http://, https://, or git://). This allows attackers to inject dangerous protocols like javascript: that execute arbitrary code when the URL is rendered or clicked by a victim user.

Attack Vector

The attack requires network access and a low-privileged account with repository edit permissions. The attacker must craft a malicious repository URL containing an XSS payload and save it to the repository configuration. When another authenticated user views the repository page, the malicious script executes in their browser context, inheriting their session privileges and API access tokens.

// Security patch from ui/src/app/shared/components/urls.ts
 import {GitUrl} from 'git-url-parse';
 import {isSHA} from './revision';
+import {isValidURL} from '../../shared/utils';
 
 const GitUrlParse = require('git-url-parse');

Source: GitHub Commit a5b4041

The patch introduces proper URL validation by importing and utilizing the isValidURL function from shared utilities, ensuring that only legitimate URL schemes are accepted and rendered in the repository configuration UI.

Detection Methods for CVE-2025-47933

Indicators of Compromise

• Repository configuration entries containing javascript:, data:, or vbscript: URL schemes
• Unusual API activity patterns following repository page views
• Unexpected modifications to application deployments or repository configurations
• Browser console errors or unexpected script execution on repository pages

Detection Strategies

• Implement Content Security Policy (CSP) headers to detect and block inline script execution attempts
• Monitor Argo CD audit logs for suspicious repository configuration changes, particularly URL field modifications
• Deploy web application firewall (WAF) rules to detect XSS payloads in API requests to repository endpoints
• Review repository configurations for URLs that do not match expected Git provider patterns

Monitoring Recommendations

• Enable comprehensive audit logging in Argo CD to track all repository configuration modifications
• Set up alerts for repository URL changes that contain non-standard protocol schemes
• Monitor for anomalous user session behavior following repository page access
• Implement browser-based security monitoring to detect client-side script injection attempts

How to Mitigate CVE-2025-47933

Immediate Actions Required

• Upgrade Argo CD to version 2.13.8, 2.14.13, or 3.0.4 immediately
• Review all existing repository configurations for potentially malicious URL values
• Audit user accounts with repository edit permissions and apply principle of least privilege
• Implement network segmentation to limit exposure of Argo CD web interface

Patch Information

Argoproj has released security patches in versions 2.13.8, 2.14.13, and 3.0.4 that address this vulnerability by implementing proper URL protocol validation. The fix adds URL sanitization to prevent dangerous protocol schemes from being stored or rendered in repository configurations. Refer to the GitHub Security Advisory GHSA-2hj5-g64g-fp6p for detailed upgrade instructions.

Workarounds

• Restrict repository edit permissions to only trusted administrators until patches can be applied
• Implement a reverse proxy or WAF in front of Argo CD to filter potentially malicious URL patterns
• Enable strict Content Security Policy headers to mitigate XSS impact if exploitation occurs
• Regularly audit repository configurations and remove any suspicious URL entries

# Verify Argo CD version after upgrade
argocd version --client

# Check for suspicious repository URLs (run periodically)
argocd repo list -o json | jq '.[] | select(.repo | test("^(?!https?://|git://|ssh://)")) | .repo'

# Apply restrictive CSP headers via Argo CD ConfigMap
kubectl patch configmap argocd-cm -n argocd --type merge -p '{"data":{"server.x-frame-options":"DENY","server.content-security-policy":"default-src '\''self'\''; script-src '\''self'\''"}}'