RCE in Pugjs Pug
CVE-2021-21353
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.
EPSS: 0.043 (90.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N.
Affected products
- Pugjs Pug — versions < 3.0.1
- Pugjs Pug-code-gen
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
- security-advisories@github.com (Exploit, Patch, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (Third Party Advisory, x_refsource_MISC, Release Notes)
- security-advisories@github.com (Product, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (Product, Third Party Advisory, x_refsource_MISC)
Frequently asked questions
- What is CVE-2021-21353?
- CVE-2021-21353 is a medium-severity vulnerability in Pugjs Pug, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 6.8/10. Published 2021-03-03.
- How severe is CVE-2021-21353?
- Medium severity. CVSS v3 base score is 6.8 out of 10.
- Is CVE-2021-21353 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.