2.3 LOW
- CVSS version (CVSS): 4.0
- Attack Vector (AV): Network (N)
- Attack Complexity (AC): High (H)
- Attack Requirement (AT): None (N)
- Privileges Required (PR): Low (L)
- User Interaction (UI): None (N)
- Vulnerable System Impact Confidentiality (VC): None (N)
- Vulnerable System Impact Integrity (VI): None (N)
- Vulnerable System Impact Availability (VA): None (N)
- Subsequent System Impact Confidentiality (SC): Low (L)
- Subsequent System Impact Integrity (SI): Low (L)
- Subsequent System Impact Availability (SA): None (N)
- Modified Attack Vector (MAV): Network (N)
- Modified Attack Complexity (MAC): High (H)
- Modified Attack Requirement (MAT): None (N)
- Modified Privileges Required (MPR): Low (L)
- Modified User Interaction (MUI): None (N)
- Modified Vulnerable System Impact Confidentiality (MVC): None (N)
- Modified Vulnerable System Impact Integrity (MVI): None (N)
- Modified Vulnerable System Impact Availability (MVA): None (N)
- Modified Subsequent System Impact Confidentiality (MSC): Low (L)
- Modified Subsequent System Impact Integrity (MSI): Low (L)
- Modified Subsequent System Impact Availability (MSA): Negligible (N)
- Safety (S): Not Defined (X)
- Automatable (AU): Not Defined (X)
- Recovery (R): Not Defined (X)
- Value Density (V): Not Defined (X)
- Vulnerability Response Effort (RE): Not Defined (X)
- Provider Urgency (U): Not Defined (X)
- Confidentiality Req. (CR): Not Defined (X)
- Integrity Req. (IR): Not Defined (X)
- Availability Req. (AR): Not Defined (X)
- Exploit Maturity (E): Not Defined (X)
by @LeSuisse Activity log
- Created suggestion
- @LeSuisse accepted
- @LeSuisse published on GitHub
Loofah `allowed_uri?` does not detect `javascript:` URIs split by numeric character references without semicolons
Loofah is a general library for manipulating and transforming HTML/XML documents and fragments, built on top of Nokogiri. From 2.25.0 until 2.25.2, Loofah::HTML5::Scrub.allowed_uri? does not reject javascript: or vbscript: URIs whose scheme is split by semicolon-less numeric character references such as :, 	, 
, or 
. CGI.unescapeHTML leaves these references encoded, so allowed_uri? reports the URL safe even though a browser decodes an encoded colon or strips encoded whitespace and executes the resulting URI scheme. This issue affects only callers that pass HTML-encoded strings directly to allowed_uri?; Loofah's default sanitize() path is not affected. This issue is fixed in version 2.25.2.
References
-
https://github.com/flavorjones/loofah/security/advisories/GHSA-5qhf-9phg-95m2 x_refsource_CONFIRM
-
https://github.com/flavorjones/loofah/pull/308 x_refsource_MISC
-
https://github.com/flavorjones/loofah/releases/tag/v2.25.2 x_refsource_MISC
Affected products
- ==>= 2.25.0, < 2.25.2