{"url":"http://public2.vulnerablecode.io/api/vulnerabilities/22940?format=json","vulnerability_id":"VCID-qz71-ek2u-8ybh","summary":"Loofah has improper detection of disallowed URIs via `allowed_uri?`\n## Summary\n\n`Loofah::HTML5::Scrub.allowed_uri?` does not correctly reject `javascript:` URIs when the scheme is split by HTML entity-encoded control characters such as `
` (carriage return), `
` (line feed), or `	` (tab).\n\n## Details\n\nThe `allowed_uri?` method strips literal control characters before decoding HTML entities. Payloads like `java
script:alert(1)` survive the control character strip, then `
` is decoded to a carriage return, producing `java\\rscript:alert(1)`.\n\nNote that the Loofah sanitizer's default `sanitize()` path is **not affected** because Nokogiri decodes HTML entities during parsing before Loofah evaluates the URI protocol. This issue only affects direct callers of the `allowed_uri?` string-level helper when passing HTML-encoded strings.\n\n## Impact\n\nApplications that call `Loofah::HTML5::Scrub.allowed_uri?` to validate user-controlled URLs and then render approved URLs into `href` or other browser-interpreted URI attributes may be vulnerable to cross-site scripting (XSS).\n\nThis only affects Loofah `2.25.0`.\n\n## Mitigation\n\nUpgrade to Loofah >= `2.25.1`.\n\n## Credit\n\nResponsibly reported by HackOne user @smlee.","aliases":[{"alias":"GHSA-2j22-pr5w-6gq8"}],"fixed_packages":[{"url":"http://public2.vulnerablecode.io/api/packages/65210?format=json","purl":"pkg:gem/loofah@2.25.1","is_vulnerable":true,"affected_by_vulnerabilities":[{"vulnerability":"VCID-amsh-qpt1-9qb7"}],"resource_url":"http://public2.vulnerablecode.io/packages/pkg:gem/loofah@2.25.1"}],"affected_packages":[{"url":"http://public2.vulnerablecode.io/api/packages/65209?format=json","purl":"pkg:gem/loofah@2.25.0","is_vulnerable":true,"affected_by_vulnerabilities":[{"vulnerability":"VCID-amsh-qpt1-9qb7"},{"vulnerability":"VCID-qz71-ek2u-8ybh"}],"resource_url":"http://public2.vulnerablecode.io/packages/pkg:gem/loofah@2.25.0"}],"references":[{"reference_url":"https://github.com/flavorjones/loofah","reference_id":"","reference_type":"","scores":[{"value":"2.3","scoring_system":"cvssv4","scoring_elements":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N"},{"value":"LOW","scoring_system":"generic_textual","scoring_elements":""}],"url":"https://github.com/flavorjones/loofah"},{"reference_url":"https://github.com/flavorjones/loofah/commit/f4ebc9c5193dde759a57541062e490e86fc7c068","reference_id":"","reference_type":"","scores":[{"value":"2.3","scoring_system":"cvssv4","scoring_elements":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N"},{"value":"LOW","scoring_system":"generic_textual","scoring_elements":""}],"url":"https://github.com/flavorjones/loofah/commit/f4ebc9c5193dde759a57541062e490e86fc7c068"},{"reference_url":"https://github.com/flavorjones/loofah/releases/tag/v2.25.1","reference_id":"","reference_type":"","scores":[{"value":"2.3","scoring_system":"cvssv4","scoring_elements":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N"},{"value":"LOW","scoring_system":"generic_textual","scoring_elements":""}],"url":"https://github.com/flavorjones/loofah/releases/tag/v2.25.1"},{"reference_url":"https://github.com/flavorjones/loofah/security/advisories/GHSA-46fp-8f5p-pf2m","reference_id":"","reference_type":"","scores":[{"value":"2.3","scoring_system":"cvssv4","scoring_elements":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N"},{"value":"LOW","scoring_system":"generic_textual","scoring_elements":""}],"url":"https://github.com/flavorjones/loofah/security/advisories/GHSA-46fp-8f5p-pf2m"},{"reference_url":"https://github.com/rubysec/ruby-advisory-db/blob/master/gems/loofah/GHSA-46fp-8f5p-pf2m.yml","reference_id":"","reference_type":"","scores":[{"value":"2.3","scoring_system":"cvssv4","scoring_elements":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N"},{"value":"LOW","scoring_system":"generic_textual","scoring_elements":""}],"url":"https://github.com/rubysec/ruby-advisory-db/blob/master/gems/loofah/GHSA-46fp-8f5p-pf2m.yml"},{"reference_url":"https://github.com/advisories/GHSA-2j22-pr5w-6gq8","reference_id":"GHSA-2j22-pr5w-6gq8","reference_type":"","scores":[{"value":"LOW","scoring_system":"cvssv3.1_qr","scoring_elements":""}],"url":"https://github.com/advisories/GHSA-2j22-pr5w-6gq8"}],"weaknesses":[{"cwe_id":79,"name":"Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","description":"The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users."},{"cwe_id":116,"name":"Improper Encoding or Escaping of Output","description":"The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved."},{"cwe_id":937,"name":"OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities","description":"Weaknesses in this category are related to the A9 category in the OWASP Top Ten 2013."},{"cwe_id":1035,"name":"OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities","description":"Weaknesses in this category are related to the A9 category in the OWASP Top Ten 2017."}],"exploits":[],"severity_range_score":"0.1 - 3","exploitability":"0.5","weighted_severity":"2.7","risk_score":1.4,"resource_url":"http://public2.vulnerablecode.io/vulnerabilities/VCID-qz71-ek2u-8ybh"}