Unhead has a Bypass of URI Scheme Sanitization in makeTagSafe via Case-Sensitivity
3Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 0epss 0.2%
exploitation probability
0.2%top 85% of all CVEs
observed exploitation
nono source reports it
Unhead is a document head and template manager. Prior to 2.1.11, The link.href check in makeTagSafe (safe.ts) uses String.includes(), which is case-sensitive. Browsers treat URI schemes case-insensitively. DATA:text/css,... is the same as data:text/css,... to the browser, but 'DATA:...'.includes('data:') returns false. An attacker can inject arbitrary CSS for UI redressing or data exfiltration via CSS attribute selectors with background-image callbacks. This vulnerability is fixed in 2.1.11.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N
Affected products
unjs · unhead