CVE-2019-10842
Arbitrary code execution (via backdoor code) was discovered in bootstrap-sass 3.2.0.3, when downloaded from rubygems.org.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (4.92%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Arbitrary code execution (via backdoor code) was discovered in bootstrap-sass 3.2.0.3, when downloaded from rubygems.org. An unauthenticated attacker can craft the ___cfduid cookie value with base64 arbitrary code to be executed via eval(), which can be leveraged to execute arbitrary code on the target system. Note that there are three underscore characters in the cookie name. This is unrelated to the __cfduid cookie that is legitimately used by Cloudflare.
- CVSS 3.0
- 9.8 CRITICALCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 4.92% probability · 92th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-94
- Affected
- getbootstrap/bootstrap-sass
- Source
- cve@mitre.org
EPSS 4.9% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://dgb.github.io/2019/04/05/bootstrap-sass-backdoor.htmlThird Party Advisory
- https://github.com/twbs/bootstrap-sass/issues/1195Issue Tracking, Third Party Advisory
- https://snyk.io/blog/malicious-remote-code-execution-backdoor-discovered-in-the-popular-bootstrap-sass-ruby-gem/Exploit, Third Party Advisory
- https://snyk.io/vuln/SNYK-RUBY-BOOTSTRAPSASS-174093Exploit, Third Party Advisory
- http://dgb.github.io/2019/04/05/bootstrap-sass-backdoor.htmlThird Party Advisory
- https://github.com/twbs/bootstrap-sass/issues/1195Issue Tracking, Third Party Advisory
- https://snyk.io/blog/malicious-remote-code-execution-backdoor-discovered-in-the-popular-bootstrap-sass-ruby-gem/Exploit, Third Party Advisory
- https://snyk.io/vuln/SNYK-RUBY-BOOTSTRAPSASS-174093Exploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.