Skip to content
Log inStart free trial

GHSA-h99w-9q5r-gjq9 CVE-2022-24790

Puma vulnerable to HTTP Request Smuggling

Critical RubyGems
Severity
9.1 / 10
Critical · CVSS 3.1
Exploit chance (EPSS)
2.19%
Chance of exploitation in the next 30 days. Higher than 82.45% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Fix
5.6.4
Upgrade puma to this version or later

Description

When using Puma behind a proxy that does not properly validate that the incoming HTTP request matches the RFC7230 standard, Puma and the frontend proxy may disagree on where a request starts and ends. This would allow requests to be smuggled via the front-end proxy to Puma.

The following vulnerabilities are addressed by this advisory:

  • Lenient parsing of Transfer-Encoding headers, when unsupported encodings should be rejected and the final encoding must be chunked.
  • Lenient parsing of malformed Content-Length headers and chunk sizes, when only digits and hex digits should be allowed.
  • Lenient parsing of duplicate Content-Length headers, when they should be rejected.
  • Lenient parsing of the ending of chunked segments, when they should end with \r\n.

The vulnerability has been fixed in 5.6.4 and 4.3.12. When deploying a proxy in front of Puma, turning on any and all functionality to make sure that the request matches the RFC7230 standard.

These proxy servers are known to have "good" behavior re: this standard and upgrading Puma may not be necessary. Users are encouraged to validate for themselves.

  • Nginx (latest)
  • Apache (latest)
  • Haproxy 2.5+
  • Caddy (latest)
  • Traefik (latest)

Affected versions

RubyGems

PackageVulnerableFixed in
puma
>= 5.0.0, < 5.6.4
5.6.4
puma
< 4.3.12
4.3.12

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

puma RubyGems → 5.6.4

bundler
bundle update puma # Gemfile: gem "puma", ">= 5.6.4"

Severity breakdown

CVSS 3.1 9.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

Weakness

CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.

How to prevent it
  • Implementation: Use a web server that employs a strict HTTP parsing procedure, such as Apache [REF-433].
  • Implementation: Use only SSL communication.
  • Implementation: Terminate the client session after each request.
  • System Configuration: Turn all pages to non-cacheable.

References

Advisories

Packages

Other links

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-2vqw-3mp8-cgmx
Puma PROXY Protocol v1 Accepts Repeated Protocol Headers on Persistent Connections
High Also affects puma
GHSA-qpgp-93vx-g8v8
Puma PROXY Protocol v1 Parser Allows Remote Memory Exhaustion
High Also affects puma
GHSA-9hf4-67fc-4vf4
Puma's header normalization allows for client to clobber proxy set headers
Medium Also affects puma
GHSA-c2f4-cvqm-65w2
Puma HTTP Request/Response Smuggling vulnerability
High Also affects puma
GHSA-68xg-gqqm-vgj8
Puma HTTP Request/Response Smuggling vulnerability
Critical Also affects puma
GHSA-rmj8-8hhh-gv5h
Puma used with Rails may lead to Information Exposure
High Also affects puma
GHSA-48w2-rm65-62xx
Puma with proxy which forwards LF characters as line endings could allow HTTP request smuggling
Low Also affects puma
GHSA-q28m-8xjw-8vr5
Puma's Keepalive Connections Causing Denial Of Service
High Also affects puma
Is this in your code?

MergeHarbor checks every repository's dependencies against this database, ranks what matters by exploitability and reachability, routes it to the owning team and opens the fix pull request.

Check your repos with MergeHarbor