CVE-2020-7670: Withdrawn HTTP Request Smuggling Vulnerability

MODERATE
Advisory Identifier: GHSA-h385-52j6-9984
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CWE-444
Published
Advisory Summary

CVE-2020-7670 is a MODERATE http request smuggling vulnerability (CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')) affecting Withdrawn libraries in the RubyGems ecosystem. The issue involves http request smuggling in agoo. Remediation is available in the latest vendor maintenance releases.

CVE-2020-7670 at a Glance

CVE Identifier CVE-2020-7670
GHSA Identifier GHSA-h385-52j6-9984
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Affected Product Withdrawn
Package Ecosystem RubyGems
Published Date
Last Updated

How to Fix CVE-2020-7670

To remediate this vulnerability, upgrade all affected Withdrawn dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

agoo fixed: Latest secure release 
Upgrade agoo to Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for agoo

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-7670, inspect your project dependencies for Withdrawn:

inspect dependencies for agoo

Analyze the terminal output to locate any version of Withdrawn in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling'), where 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. In Withdrawn, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

# Withdrawn reason Withdrawn on 1/13/2021 due to [this comment from the maintainer](https://github.com/ohler55/agoo/issues/88#issuecomment-723580783). This is no longer considered a vulnerability. # Original description agoo through 2.12.3 allows request smuggling attacks where agoo is used as a backend and a frontend proxy also being vulnerable. It is possible to conduct HTTP request smuggling attacks by sending the Content-Length header twice. Furthermore, invalid Transfer Encoding headers were found to be parsed as valid which could be leveraged for TE:CL smuggling attacks.

CVE-2020-7670 Affected Withdrawn Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
agoo
gem/agoo
RubyGems
≤ 2.13.0

References

NVD — CVE-2020-7670 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-7670
Withdrawn Source Repository REPOSITORY
https://github.com/ohler55/agoo/issues/88
Security Fix Commit FIX COMMIT
https://github.com/ohler55/agoo/commit/23d03535cf7b50d679a60a953a0cae9519a4a130
snyk.io/vuln/snyk-ruby-agoo... WEB
https://snyk.io/vuln/SNYK-RUBY-AGOO-569137

Frequently Asked Questions

What is CVE-2020-7670?
CVE-2020-7670 is a security vulnerability in Withdrawn involving HTTP Request Smuggling in Agoo under CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling').
Which Withdrawn versions are affected?
Affected versions include releases prior to current release patches across affected packages: agoo.
What version fixes CVE-2020-7670?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is agoo affected?
Yes, agoo is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What CWE is associated with CVE-2020-7670?
CVE-2020-7670 is classified under 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 can I check RubyGems dependencies for CVE-2020-7670?
Run the dependency tree command: 'inspect dependencies for agoo'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-h385-52j6-9984",
  "modified" : "2021-01-13T19:25:43Z",
  "published" : "2020-10-20T19:15:38Z",
  "withdrawn" : "2021-01-13T19:25:43Z",
  "aliases" : [ "CVE-2020-7670" ],
  "summary" : "Withdrawn: HTTP Request Smuggling in Agoo",
  "details" : "# Withdrawn reason\nWithdrawn on 1/13/2021 due to [this comment from the maintainer](https://github.com/ohler55/agoo/issues/88#issuecomment-723580783).  This is no longer considered a vulnerability.\n\n# Original description\nagoo through 2.12.3 allows request smuggling attacks where agoo is used as a backend and a frontend proxy also being vulnerable. It is possible to conduct HTTP request smuggling attacks by sending the Content-Length header twice. Furthermore, invalid Transfer Encoding headers were found to be parsed as valid which could be leveraged for TE:CL smuggling attacks.",
  "severity" : [ ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "agoo"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "2.13.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-7670"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ohler55/agoo/issues/88"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ohler55/agoo/commit/23d03535cf7b50d679a60a953a0cae9519a4a130"
  }, {
    "type" : "WEB",
    "url" : "https://snyk.io/vuln/SNYK-RUBY-AGOO-569137"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-444" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2020-10-20T19:04:34Z",
    "nvd_published_at" : null
  }
}