Request smuggling via undiscarded HEAD request body
Published Apr 22, 2025 · Updated Nov 3, 2025
HTTP request smuggling in OpenResty lua-nginx-module 0.10.26 and earlier allows remote attackers to inject requests via a crafted HEAD request. The ngx_http_lua_send_chain_link path returns for HEAD responses before ngx_http_discard_request_body advances past the declared body, so body bytes become another request. Exploitation requires a chained front-end proxy with a persistent upstream connection, enabling access-control bypass, cross-user response injection, or response disclosure.
Summary
What happened
HTTP request smuggling in OpenResty lua-nginx-module 0.10.26 and earlier allows remote attackers to inject requests via a crafted HEAD request. The ngx_http_lua_send_chain_link path returns for HEAD responses before ngx_http_discard_request_body advances past the declared body, so body bytes become another request. Exploitation requires a chained front-end proxy with a persistent upstream connection, enabling access-control bypass, cross-user response injection, or response disclosure.
The record
- CVE
- CVE-2024-33452
- Published
- Apr 22, 2025
- Updated
- Nov 3, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-444, CAPEC-33, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 22, 2025CVE publishedPublication date reported by the CVE source.
- Nov 3, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- OpenResty_HEAD_HRS proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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