5.8 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
NONE
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
0.001 Low
EPSS
Percentile
27.8%
RFC 9112 Section 7.1 defined the format of chunk size, chunk data and chunk extension (detailed ABNF is in Appendix section).
In summary:
However, we found that Falcon has following behaviors while disobey the corresponding RFCs.
This behavior can lead to desync when forwarding through multiple HTTP parsers, potentially results in HTTP request smuggling and firewall bypassing. Note that while these issues were reproduced in Falcon (the server), the issue is with protocol-http1
which implements the HTTP/1 protocol parser. We have not yet been advised of any real world exploit or practical attack.
Fixed in protocol-http1
v0.15.1+.
None.
github.com/rubysec/ruby-advisory-db/blob/master/gems/protocol-http1/CVE-2023-38697.yml
github.com/socketry/protocol-http1
github.com/socketry/protocol-http1/commit/e11fc164fd2b36f7b7e785e69fa8859eb06bcedd
github.com/socketry/protocol-http1/pull/20
github.com/socketry/protocol-http1/security/advisories/GHSA-6jwc-qr2q-7xwj
nvd.nist.gov/vuln/detail/CVE-2023-38697
www.rfc-editor.org/rfc/rfc9112#name-chunked-transfer-coding