Resource exhaustion in Sass-Lang Libsass

CVE-2018-19837

In LibSass prior to 3.5.5, Sass::Eval::operator()(Sass::Binary_Expression*) inside eval.cpp allows attackers to cause a denial-of-service resulting from stack consumption via a crafted sass file, because of certain incorrect parsing of '%' as a modulo operator in parser.cpp.

Vulnerability class: DoS (Denial of Service)

EPSS: 0.018 (76.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2018-19837?
CVE-2018-19837 is a medium-severity vulnerability in Sass-Lang Libsass, classified under Uncontrolled Resource Consumption. CVSS score: 6.5/10. Published 2018-12-04.
How severe is CVE-2018-19837?
Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2018-19837 known to be exploited?
6 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.