CVE-2021-21353

What it is

Pug is an npm package which is a high-performance template engine. In pug before version 3.0.1, if a remote attacker was able to control the `pretty` option of the pug compiler, e.g. if you spread a user provided object such as the query parameters of a request into the pug template inputs, it was possible for them to achieve remote code execution on the node.js backend. This is fixed in version 3.0.1. This advisory applies to multiple pug packages including "pug", "pug-code-gen". pug-code-gen has a backported fix at version 2.0.3. This advisory is not exploitable if there is no way for un-trusted input to be passed to pug as the `pretty` option, e.g. if you compile templates in advance before applying user input to them, you do not need to upgrade.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data tampering.

Exploit odds

4.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2021-03-03 02:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-11-02 18:18 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 4.3% in the next 30 days (EPSS).
• Severity: 6.8 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2021-03-03 02:15 UTC

Last modified

2026-11-02 18:18 UTC

Exploit probability

4.3% · EPSS, next 30 days

Weakness

CWE-74

Record status

Analyzed

Affected

• Pugjs Pug < 3.0.1
• Pugjs pug-code-gen < 2.0.3
• Pugjs pug-code-gen < 3.0.2

Attack profile CVSS 3.1 · 6.8

Attack vector

Network

Complexity

High

Privileges needed

None

User interaction

None

Scope

Changed

Confidentiality

None

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-21353.md and follow it. Check whether this project is affected by CVE-2021-21353. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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