HTTP Request/Response Smuggling in puma
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 1 fixed, 1 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA, GitHub and Red Hat.
Summary
Puma is a web server for Ruby/Rack applications built for parallelism. Prior to version 6.4.2, puma exhibited incorrect behavior when parsing chunked transfer encoding bodies in a way that allowed HTTP request smuggling. Fixed versions limits the size of chunk extensions. Without this limit, an attacker could cause unbounded resource (CPU, network bandwidth) consumption. This vulnerability has been fixed in versions 6.4.2 and 5.6.8.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| puma | puma | before 5.6.8; 6.0.0 to before 6.4.2 | 5.6.8, 6.4.2 | Patch available | CNA |
| — | puma (RubyGems) | 6.0.0 to before 6.4.2 | 6.4.2 | Patch available | GHSA-c2f4-cvqm-65w2 |
| — | puma (RubyGems) | before 5.6.8 | 5.6.8 | Patch available | GHSA-c2f4-cvqm-65w2 |
- puma Vendorpuma Affected before 5.6.8; 6.0.0 to before 6.4.2 Fixed in 5.6.8, 6.4.2 Patch available CNA
- puma (RubyGems) Vendor— Affected 6.0.0 to before 6.4.2 Fixed in 6.4.2 Patch available GHSA-c2f4-cvqm-65w2
- puma (RubyGems) Vendor— Affected before 5.6.8 Fixed in 5.6.8 Patch available GHSA-c2f4-cvqm-65w2
Remediation
- Fix · CNA puma (puma) Fixed in 5.6.8, 6.4.2
- Fix · GHSA-c2f4-cvqm-65w2 puma (RubyGems) Fixed in 6.4.2 Advisory →
- Fix · GHSA-c2f4-cvqm-65w2 puma (RubyGems) Fixed in 5.6.8 Advisory →
Red Hat 1 advisory
- RHSA-2024:2010 Released 2024-04-23 · Red Hat rating ImportantSatellite 6.15.0 release
- Red Hat Satellite 6.15 for RHEL 8 foreman-3.9.1.6-1.el8sat, foreman-cli-3.9.1.6-1.el8sat, foreman-debug-3.9.1.6-1.el8sat +28
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Storage 3 | Affected | No fix planned: Out of support scope |
| Red Hat Satellite 6.15 for RHEL 8 | Fixed | RHSA-2024:2010 |
Not affected: 2 products
- Red Hat Satellite 6
- Red Hat Satellite 6.15 for RHEL 8
Timeline
- 2026-10-02 Threatist record created from CVE-2024-21647
- 2026-10-03 Alias added: GHSA-c2f4-cvqm-65w2
References
Advisory 2
Other 5
- https://github.com/puma/puma/commit/60d5ee3734adc8cee85c3f0561af392448fe19b7
- https://github.com/puma/puma/commit/bbb880ffb6debbfdea535b4b3eb2204d49ae151d
- https://github.com/puma/puma
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/puma/CVE-2024-21647.yml
- https://lists.debian.org/debian-lts-announce/2024/11/msg00004.html
More Puma vulnerabilities
- TI-2022-08603 HTTP Request Smuggling in puma CVSS 3.1CRITICAL 9.1
- TI-2023-21048 Inconsistent Interpretation of HTTP Requests in puma CVSS 3.1CRITICAL 9.8
- TI-2022-07686 Information Exposure when using Puma with Rails CVSS 3.1HIGH 8.0
- TI-2020-08950 HTTP Smuggling via Transfer-Encoding Header in Puma CVSS 3.1HIGH 7.5
- TI-2020-08951 HTTP Smuggling via Transfer-Encoding Header in Puma CVSS 3.1HIGH 7.5
- TI-2020-04303 HTTP Response Splitting in Puma CVSS 3.1HIGH 7.5
Sources
- CVE-2024-21647 · CVE Program
- CVE-2024-21647 · NVD
- FIRST EPSS
- GHSA-c2f4-cvqm-65w2 · GitHub Advisory Database · CC BY 4.0
- CVE-2024-21647 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences