Vulnerability identifier: #VU51267

Vulnerability risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-21353

CWE-ID: CWE-94

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Pug
Web applications / Modules and components for CMS

Vendor: Pugjs

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to improper input validation in visitMixin and visitMixinBlock within the "pretty" option. A remote attacker can send a specially crafted request and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Pug: 1.0.2 - 3.0.0

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External links
http://github.com/pugjs/pug/commit/991e78f7c4220b2f8da042877c6f0ef5a4683be0
http://github.com/pugjs/pug/issues/3312
http://github.com/pugjs/pug/pull/3314
http://github.com/pugjs/pug/releases/tag/pug%403.0.1
http://github.com/pugjs/pug/security/advisories/GHSA-p493-635q-r6gr
http://www.npmjs.com/package/pug
http://www.npmjs.com/package/pug-code-gen

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.