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CVE-2023-2512 Detail


Prior to version v1.20230419.0, the FormData API implementation was subject to an integer overflow. If a FormData instance contained more than 2^31 elements, the forEach() method could end up reading from the wrong location in memory while iterating over elements. This would most likely lead to a segmentation fault, but could theoretically allow arbitrary undefined behavior. In order for the bug to be exploitable, the process would need to be able to allocate 160GB of RAM. Due to this, the bug was never exploitable on the Cloudflare Workers platform, but could theoretically be exploitable on deployments of workerd running on machines with a huge amount of memory. Moreover, in order to be remotely exploited, an attacker would have to upload a single form-encoded HTTP request of at least tens of gigabytes in size. The application code would then have to use request.formData() to parse the request and formData.forEach() to iterate over this data. Due to these limitations, the exploitation likelihood was considered Low. A fix that addresses this vulnerability has been released in version v1.20230419.0 and users are encouraged to update to the latest version available.


CVSS 3.x Severity and Metrics:

Base Score:  8.1 HIGH
Vector:  CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Nist CVSS score does not match with CNA score
CNA:  Cloudflare, Inc.
Base Score:  6.5 MEDIUM
Vector:  CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H

NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: It is possible that the NVD CVSS may not match that of the CNA. The most common reason for this is that publicly available information does not provide sufficient detail or that information simply was not available at the time the CVSS vector string was assigned.

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Hyperlink Resource
https://github.com/cloudflare/workerd/releases/tag/v1.20230419.0 Release Notes 
https://github.com/cloudflare/workerd/security/advisories/GHSA-8vx6-69vg-c46f Vendor Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-190 Integer Overflow or Wraparound cwe source acceptance level NIST  
CWE-125 Out-of-bounds Read Reference acceptance level Cloudflare, Inc.  

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Change History

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Quick Info

CVE Dictionary Entry:
NVD Published Date:
NVD Last Modified:
Cloudflare, Inc.