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lambdaisland/uri `authority-regex` returns the wrong authority

Moderate severity GitHub Reviewed Published Mar 27, 2023 in lambdaisland/uri • Updated Apr 4, 2023

Package

maven lambdaisland:uri (Maven)

Affected versions

< 1.14.120

Patched versions

1.14.120

Description

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

@plexus plexus published to lambdaisland/uri Mar 27, 2023
Published by the National Vulnerability Database Mar 27, 2023
Published to the GitHub Advisory Database Mar 27, 2023
Reviewed Mar 27, 2023
Last updated Apr 4, 2023

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

EPSS score

0.087%
(38th percentile)

CVE ID

CVE-2023-28628

GHSA ID

GHSA-cp4w-6x4w-v2h5

Source code

Credits

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