css_parser allows to MITM included https css urls
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.8epss 0.1%
exploitation probability
0.1%top 96% of all CVEs
observed exploitation
nono source reports it
css_parser is a Ruby CSS parser. Prior to 2.1.0 and 1.22.0, the CSS Parser gem does not validate HTTPS connections, allowing a Man-in-the-Middle (MITM) attacker to inject or modify CSS content when stylesheets are loaded via HTTPS. The connection is established with OpenSSL::SSL::VERIFY_NONE, meaning any HTTPS certificate—even entirely untrusted—will be accepted without validation. This vulnerability is fixed in 2.1.0 and 1.22.0.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Affected products
premailer · css_parserReferences
https://github.com/premailer/css_parser/commit/35e689c904225add78e0c488cf04bad052666449https://github.com/premailer/css_parser/commit/e0c95d5abe91b237becb90ff316531a6547ada18https://github.com/premailer/css_parser/issues/185https://github.com/premailer/css_parser/security/advisories/GHSA-ff6c-w6qf-7xqc