Authorization Before Parsing and Canonicalization in jetty

Description

Release 9.4.37 introduced a more precise implementation of RFC3986 with regards to URI decoding, together with some new compliance modes to optionally allow support of some URI that may have ambiguous interpretation within the Servlet specified API methods behaviours. The default mode allowed % encoded . characters to be excluded for URI normalisation, which is correct by the RFC, but is not assumed by common Servlet implementations. The default compliance mode allows requests with URIs that contain %2e or %2e%2e segments to access protected resources within the WEB-INF directory. For example a request to /context/%2e/WEB-INF/web.xml can retrieve the web.xml file. This can reveal sensitive information regarding the implementation of a web application. Workarounds found by HttpCompliance mode RFC7230_NO_AMBIGUOUS_URIS can be enabled by updating start.d/http.ini to include: jetty.http.compliance=RFC7230_NO_AMBIGUOUS_URIS.

Basic information

Type
reviewed
Severity
medium
Advisory on GitHub
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Repository advisory
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Source code
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Published (advisory)
2021-04-06 17:31:01 UTC
Updated
2023-02-01 05:05:22 UTC
GitHub reviewed
2021-04-02 20:28:10 UTC
NVD published
2021-04-01

EPSS Score

Score Percentile
93.48% 99.82%

CVSS Scores

Base score Version Severity Vector
5.3 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.

Identifiers

CWEs

CWE id Name
CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
CWE-551 Incorrect Behavior Order: Authorization Before Parsing and Canonicalization
CWE-863 Incorrect Authorization

Credits

  • charlesk40 (analyst)

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
maven org.eclipse.jetty:jetty-webapp >= 9.4.37, < 9.4.39 9.4.39

References

cvelogic Threat Intelligence