Listen to this Post
The vulnerability occurs when the AWS SDK for Swift constructs endpoint URLs for service calls without validating the format of the provided region string. An attacker with access to the application’s runtime environment—such as through environment variables, configuration files, or code injection—can set the region parameter to an invalid value. This value could contain special characters, spaces, or malformed labels that do not comply with DNS hostname standards. When the SDK uses this invalid region to build the service endpoint, it may generate a URL that points to a non-existent domain or a host not controlled by AWS. This could lead to AWS API calls being improperly routed, resulting in denial of service if the domain is unreachable, or in potential security risks if combined with other vulnerabilities like DNS hijacking. The SDK’s previous behavior relied on the shared responsibility model, assuming correct configuration. The enhancement adds validation to ensure the region string is a valid host label, typically meaning it must contain only alphanumeric characters and hyphens, and must start and end with an alphanumeric character, preventing the formation of malformed URLs.
Platform: AWS SDK Swift
Version: Below 1.5.79
Vulnerability: Invalid Region Input
Severity: LOW
date: 2025-11-06
Prediction: Patched 2025-11-06
What Undercode Say:
Analytics
Showing bash commands and codes related to the blog
export AWS_REGION="invalid@@region" swift package show-dependencies
import AWSSDK let config = try AWSConfig(region: "us-east-1") // Pre-patch: region "invalid!!" accepted // Post-patch: validation error thrown
How to Exploit:
Set invalid region via environment variable or configuration.
Protection from this CVE
Update SDK version.
Impact:
Low severity misrouting.
🎯Let’s Practice Exploiting & Learn Patching For Free:
Sources:
Reported By: github.com
Extra Source Hub:
Undercode
