Alibaba Cloud OSS Bucket Public Listing Enabled Detection Scanner

Alibaba Cloud OSS is commonly used by businesses and developers for storing and managing large volumes of data. It is an object storage service that supports various data types, including images, videos, and files. Organizations leverage OSS for its scalability and cost-effectiveness, allowing easy access to stored data via the internet. The storage service is integral for applications requiring high availability and durability of data storage. By providing APIs for seamless integration, OSS is utilized in environments where data accessibility and collaborative workflows are essential. The service is popular among devops teams for its support in continuous integration and deployment pipelines.

The vulnerability detected by this scanner involves the misconfiguration of Alibaba Cloud OSS Buckets, where buckets are publicly accessible. This configuration exposure allows anonymous users to list the objects within the bucket, which may include sensitive information. Misconfigured buckets can lead to data breaches, exposing confidential data to unauthorized parties. The vulnerability primarily arises due to improper access control settings or incomplete bucket policies. It is a critical security issue as it opens up the data to anyone with internet access. Addressing this vulnerability is crucial to maintaining data confidentiality and security.

This configuration disclosure vulnerability in Alibaba Cloud OSS is caused by the enabling of public access to object storage buckets. The vulnerability is detected by checking for the presence of the "ListBucketResult" and "AliyunOSS" headers in HTTP responses from the bucket. When public listing is enabled, the endpoint exposes a list of stored contents, identifiable by XML tags like "", "", and "". The issue is technical as it involves misconfigured access permissions allowing unauthorized directory listings. Identification also involves validating HTTP status codes and content types associated with the bucket.

Exploitation of this vulnerability could lead to various potential effects, including unauthorized data access and potential data breaches. Sensitive data, if exposed, could be used for malicious purposes, resulting in privacy violations and financial loss. Unintended data exposure might incur unexpected charges on the Alibaba Cloud bill. Organizations could face reputational damage due to unauthorized data access, which impacts customer trust and compliance with data protection regulations. Moreover, the availability of publicly accessible data simplifies data breach attempts by enabling attackers to identify sensitive information quickly.

REFERENCES

• https://www.alibabacloud.com/help/en/oss/user-guide/block-public-access
• https://www.trendmicro.com/cloudoneconformity/knowledge-base/alibaba-cloud/AlibabaCloud-OSS/publicly-accessible-oss-bucket.html