Upstream access-control bypass via trailing-newline URL matching
Published Dec 7, 2021 · Updated Aug 4, 2024
Authentication bypass in Django 2.2–3.2 allows remote attackers to bypass upstream URL-path access controls via trailing-newline HTTP requests. Affected URL resolver endpoint patterns used regex search with a dollar anchor, which accepted a newline suffix; the patch switches endpoint matching to fullmatch and uses a \Z anchor. Exploitation requires an upstream control that relies on Django-resolved URL paths and a reachable HTTP application, enabling unauthorized access to routes otherwise blocked by path-based rules.
Summary
What happened
Authentication bypass in Django 2.2–3.2 allows remote attackers to bypass upstream URL-path access controls via trailing-newline HTTP requests. Affected URL resolver endpoint patterns used regex search with a dollar anchor, which accepted a newline suffix; the patch switches endpoint matching to fullmatch and uses a \Z anchor. Exploitation requires an upstream control that relies on Django-resolved URL paths and a reachable HTTP application, enabling unauthorized access to routes otherwise blocked by path-based rules.
The record
- CVE
- CVE-2021-44420
- Published
- Dec 7, 2021
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 7, 2021CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
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Attacks
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Technologies
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