CVE-2021-36770

Name: CVE-2021-36770
Creator: NVD / NIST
Published: 2021-08-11T23:15:07.707+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 1.40%

Last modified Jun 17, 2026

CVE-2021-36770 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. 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). EPSS estimates a 1.40% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Probability

1.40%

69.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-427

Affected Software

Vendor	Product	Versions
P5-Encode Project	P5-Encode	>= 3.05, < 3.12
Fedoraproject	Fedora	34
Fedoraproject	Fedora	33

References

https://github.com/Perl/perl5/commit/c1a937fef07c061600a0078f4cb53fe9c2136bb9Patch, Third Party Advisory
https://github.com/dankogai/p5-encode/commit/527e482dc70b035d0df4f8c77a00d81f8d775c74Patch, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5NDGQSGMEZ75FJGBKNYC75OTO7TF7XHB/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6KOZYD7BH2DNIAEZ2ZL4PJ4QUVQI6Y33/
https://metacpan.org/dist/Encode/changesThird Party Advisory
https://news.cpanel.com/unscheduled-tsr-10-august-2021/Third Party Advisory
https://security-tracker.debian.org/tracker/CVE-2021-36770Third Party Advisory
https://security.netapp.com/advisory/ntap-20210909-0003/Third Party Advisory
https://github.com/Perl/perl5/commit/c1a937fef07c061600a0078f4cb53fe9c2136bb9Patch, Third Party Advisory
https://github.com/dankogai/p5-encode/commit/527e482dc70b035d0df4f8c77a00d81f8d775c74Patch, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5NDGQSGMEZ75FJGBKNYC75OTO7TF7XHB/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6KOZYD7BH2DNIAEZ2ZL4PJ4QUVQI6Y33/
https://metacpan.org/dist/Encode/changesThird Party Advisory
https://news.cpanel.com/unscheduled-tsr-10-august-2021/Third Party Advisory
https://security-tracker.debian.org/tracker/CVE-2021-36770Third Party Advisory
https://security.netapp.com/advisory/ntap-20210909-0003/Third Party Advisory
https://security.netapp.com/advisory/ntap-20241108-0002/

Timeline

Published: Aug 11, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-36770?

How severe is CVE-2021-36770?

CVE-2021-36770 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 1.40% probability of exploitation in the next 30 days.

How do I fix CVE-2021-36770?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-36770?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST