What’s Vulnerable › Vulnerabilities
CVE-2021-36770
- Severity: high (CVSS 7.8 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 1.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2021-08-11 · updated 2026-06-17
- Weakness: CWE-427
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.
Affected products
- Fedoraproject Fedora: 34, 33
- P5-Encode Project P5-Encode: from 3.05 before 3.12 — fixed in 3.12
How to fix
Upgrade to a fixed version: P5-Encode Project P5-Encode 3.12. Check the vendor advisory for mitigations.
References
- https://github.com/Perl/perl5/commit/c1a937fef07c061600a0078f4cb53fe9c2136bb9
- https://github.com/dankogai/p5-encode/commit/527e482dc70b035d0df4f8c77a00d81f8d775c74
- 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/changes
- https://news.cpanel.com/unscheduled-tsr-10-august-2021/
- https://security-tracker.debian.org/tracker/CVE-2021-36770
- https://security.netapp.com/advisory/ntap-20210909-0003/
- https://github.com/Perl/perl5/commit/c1a937fef07c061600a0078f4cb53fe9c2136bb9
- https://github.com/dankogai/p5-encode/commit/527e482dc70b035d0df4f8c77a00d81f8d775c74
- 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/
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