vulnerability / NVI-00016090 / Revision 1
Astro: Authorization Bypass via Decode Iteration Limit and Rewrite Path Canonicalization Mismatch
GitHub lists this reviewed advisory for astro. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
8.2 high
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
astro
source listed>= 6.4.7, < 6.4.8
# Astro 6.4.7 Authorization Bypass via Decode Iteration Limit and Rewrite Path Canonicalization Mismatch ## Summary Astro 6.4.7 appears to reintroduce a middleware authorization bypass pattern when a request path is encoded more deeply than the newly introduced iterative URL decoder's maximum decoding depth. The issue occurs because Astro performs authorization decisions on a partially decoded pathname after reaching a decoding iteration cap, while later route matching logic performs an additional `decodeURI()` operation and resolves the request to a protected route. As a result, middleware and route matching may operate on different pathname representations, enabling authorization bypasses under specific application patterns. **Potential CWE:** CWE-647 – Use of Non-Canonical URL Paths for Authorization Decisions --- ## Vulnerable Pattern Middleware authorization sees: ```text /%61dmin ``` Later rewrite route matching sees: ```text /admin ``` This discrepancy allows a request that bypasses middleware checks to subsequently resolve to a protected route. --- ## Root Cause ### Iterative Decoding Logic PR #16967 introduced iterative URI decoding: ```js let iterations =
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
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04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
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- GHSA-vj59-8hwv-xxmv ↗
GitHub Advisory Database · vendor advisory
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Public revision history
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- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.