Vulnerability Report

CVE-2021-36770

Title: Privilege Escalation via Trojan Encode::ConfigLocal

Privilege Escalation

Proof Of Concept

No public PoC currently indexed for CVE-2021-36770.

CWE Category CWE-427
Published Date Aug 11, 2021
Modified Date Nov 03, 2025
Exploit Status Not Found
Score 7.8 CVSS v3.1
Exploit Probability (EPSS)
1.40%

Vulnerability Summary

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 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.

Impacted Vendors

P
perl 1
L
larry_wall 1
P
p5-encode_project 1

Reference Links

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/ 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://security.netapp.com/advisory/ntap-20241108-0002/
CVSS v3.1
Source Entity [email protected]
Severity HIGH
7.8
Attack Vector
LOCAL
Complexity
LOW
Privileges
N/A
Interaction
REQUIRED
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS v2.0
Source Entity [email protected]
Severity MEDIUM
6.8
Access Vector
N/A
Authentication
N/A
RAW VECTOR AV:N/AC:M/Au:N/C:P/I:P/A:P

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2021-36770 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data or affected products updated.

PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector LOCAL
Complexity LOW
Privileges N/A
Interaction REQUIRED
CVSS Vector String CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected Stack

No specific products linked.