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CVE-2025-27136 Detail

Description

LocalS3 is an Amazon S3 mock service for testing and local development. Prior to version 1.21, the LocalS3 service's bucket creation endpoint is vulnerable to XML External Entity (XXE) injection. When processing the CreateBucketConfiguration XML document during bucket creation, the service's XML parser is configured to resolve external entities. This allows an attacker to declare an external entity that references an internal URL, which the server will then attempt to fetch when parsing the XML. The vulnerability specifically occurs in the location constraint processing, where the XML parser resolves external entities without proper validation or restrictions. When the external entity is resolved, the server makes an HTTP request to the specified URL and includes the response content in the parsed XML document. This vulnerability can be exploited to perform server-side request forgery (SSRF) attacks, allowing an attacker to make requests to internal services or resources that should not be accessible from external networks. The server will include the responses from these internal requests in the resulting bucket configuration, effectively leaking sensitive information. The attacker only needs to be able to send HTTP requests to the LocalS3 service to exploit this vulnerability.


Metrics

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  GitHub, Inc.
CVSS-BT 5.5 MEDIUM
Vector:  CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:P

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://github.com/Robothy/local-s3/commit/d6ed756ceb30c1eb9d4263321ac683d734f8836f
https://github.com/Robothy/local-s3/security/advisories/GHSA-g6wm-2v64-wq36

Weakness Enumeration

CWE-ID CWE Name Source
CWE-611 Improper Restriction of XML External Entity Reference GitHub, Inc.  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2025-27136
NVD Published Date:
03/10/2025
NVD Last Modified:
03/10/2025
Source:
GitHub, Inc.