Unauthenticated service exhaustion via unlimited chunk accumulation
Published Jul 10, 2025 · Updated Jul 10, 2025
Uncontrolled resource consumption in cpp-httplib before 0.23.0 allows remote attackers to exhaust server memory with chunked requests. The chunked-body parser appends decoded chunks to the accumulated request body without enforcing a total payload limit. Any reachable HTTP server using an affected build can consume memory until its process crashes or becomes unresponsive; no authentication or user action is required.
Summary
What happened
Uncontrolled resource consumption in cpp-httplib before 0.23.0 allows remote attackers to exhaust server memory with chunked requests. The chunked-body parser appends decoded chunks to the accumulated request body without enforcing a total payload limit. Any reachable HTTP server using an affected build can consume memory until its process crashes or becomes unresponsive; no authentication or user action is required.
The record
- CVE
- CVE-2025-53629
- Published
- Jul 10, 2025
- Updated
- Jul 10, 2025
- Vendor
- Yuji Hirose
- Product
- cpp-httplib
- Classifications
- CWE-400, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 10, 2025CVE publishedPublication date reported by the CVE source.
- Jul 10, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 0.23.0
What conditions does exploitation require?
What is affected?
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
- GitHub advisory indefinite-chunk Python proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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