CVE-2021-28963

What it actually does

Allows content injection because template generation uses attacker-controlled parameters in the affected service provider components.

Why it matters to the business

Attackers can alter rendered content, leading to potential misinformation, user deception, or degraded trust in application outputs; low exploit likelihood reduces immediate urgency despite wide ecosystem presence in dependent projects.

How an attack unfolds

An attacker supplies specially crafted parameters in requests to endpoints that feed into template generation, causing the system to incorporate and render attacker-supplied content without validation.

How to fix it

Upgrade vrana/adminer to commit 85fc4b18e21ee6e46d8abf2bdfa87550d55e4732 and netflix/zuul to commit e5a66188f69fc84f56790130ae8b2646f6307384; verify all downstream dependents are updated.

How to confirm the fix worked

Confirm deployed versions match or exceed the listed fixed commits; test template generation with known malicious parameters to ensure injection is blocked.

Typical attack path

1. Locate endpoints or functions that invoke template rendering with external input
2. Craft requests containing malicious parameters designed to influence template output
3. Submit the requests to trigger generation and observe successful content injection
4. Leverage the injected content for further impact such as phishing or data manipulation

How to detect it

Inspect web server and application logs for requests containing unexpected or encoded parameters passed to template functions; review rendered output for signs of injected strings not present in source templates.

What your security team should do

• Prioritize upgrades to the specified fixed commits across all instances
• Review and harden template handling logic to reject untrusted parameters
• Scan dependency graphs for additional copies of the vulnerable packages
• Monitor application logs for anomalous parameter values in template-related requests