CVE-2018-19837 — In LibSass prior to 3

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

01What is this vulnerability?

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.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2018-12-04T09:00:00.000Z
• Last modified: 2024-08-05T11:44:20.721Z

09References

• github.com — https://github.com/sass/libsass/issues/2659
• github.com — https://github.com/sass/libsass/commit/210fdff7a65370c2ae24e022a2b35da8c423cc5f
• lists.opensuse.org — http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00047.html
• lists.opensuse.org — http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00051.html
• lists.opensuse.org — http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00027.html