Headline
GHSA-cp4w-6x4w-v2h5: lambdaisland/uri `authority-regex` returns the wrong authority
Summary
authority-regex allows an attacker to send malicious URLs to be parsed by the lambdaisland/uri and return the wrong authority. This issue is similar to CVE-2020-8910.
Details
https://github.com/lambdaisland/uri/blob/d3355fcd3e235238f4dcd37be97787a84e580072/src/lambdaisland/uri.cljc#L9
This regex doesn’t handle the backslash (\) character in the username correctly, leading to a wrong output.
Payload: https://example.com\\@google.com
The returned host is google.com, but the correct host should be example.com.
urllib3 (Python) and google-closure-library (Javascript) return example.com as the host. Here the correct (or current) regex used by google-closure-library:
https://github.com/google/closure-library/blob/0e567abedb058e9b194a40cfa3ad4c507653bccf/closure/goog/uri/utils.js#L189
PoC
(ns poc.core)
(require '[lambdaisland.uri :refer (uri)])
(def myurl "https://example.com\\@google.com")
(defn -main
[]
(println myurl)
(println (:host (uri myurl)))
)
Impact
The library returns the wrong authority, and it can be abused to bypass host restrictions.
Reference
WHATWG Living URL spec, section 4.4 URL Parsing, host state: https://url.spec.whatwg.org/#url-parsing
Summary
authority-regex allows an attacker to send malicious URLs to be parsed by the lambdaisland/uri and return the wrong authority. This issue is similar to CVE-2020-8910.
Details
https://github.com/lambdaisland/uri/blob/d3355fcd3e235238f4dcd37be97787a84e580072/src/lambdaisland/uri.cljc#L9
This regex doesn’t handle the backslash () character in the username correctly, leading to a wrong output.
Payload: https://example.com\@google.com
The returned host is google.com, but the correct host should be example.com.
urllib3 (Python) and google-closure-library (Javascript) return example.com as the host. Here the correct (or current) regex used by google-closure-library:
https://github.com/google/closure-library/blob/0e567abedb058e9b194a40cfa3ad4c507653bccf/closure/goog/uri/utils.js#L189
PoC
(ns poc.core)
(require '[lambdaisland.uri :refer (uri)])
(def myurl "https://example.com\\@google.com")
(defn -main
[]
(println myurl)
(println (:host (uri myurl)))
)
Impact
The library returns the wrong authority, and it can be abused to bypass host restrictions.
Reference
WHATWG Living URL spec, section 4.4 URL Parsing, host state: https://url.spec.whatwg.org/#url-parsing
References
- GHSA-cp4w-6x4w-v2h5
- https://nvd.nist.gov/vuln/detail/CVE-2023-28628
- lambdaisland/uri@f46db3e
- https://github.com/google/closure-library/blob/0e567abedb058e9b194a40cfa3ad4c507653bccf/closure/goog/uri/utils.js#L189
- https://github.com/lambdaisland/uri/blob/d3355fcd3e235238f4dcd37be97787a84e580072/src/lambdaisland/uri.cljc#L9
- https://github.com/lambdaisland/uri/releases/tag/v1.14.120
Related news
lambdaisland/uri is a pure Clojure/ClojureScript URI library. In versions prior to 1.14.120 `authority-regex` allows an attacker to send malicious URLs to be parsed by the `lambdaisland/uri` and return the wrong authority. This issue is similar to but distinct from CVE-2020-8910. The regex in question doesn't handle the backslash (`\`) character in the username correctly, leading to a wrong output. ex. a payload of `https://example.com\\@google.com` would return that the host is `google.com`, but the correct host should be `example.com`. Given that the library returns the wrong authority this may be abused to bypass host restrictions depending on how the library is used in an application. Users are advised to upgrade. There are no known workarounds for this vulnerability.