CVE-2020-10687: Undertow core HTTP Request Smuggling Vulnerability

MODERATE
Advisory Identifier: GHSA-p9w3-gwc2-cr49
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CVSS 4.8
CWE-444
Published
Advisory Summary

CVE-2020-10687 is a MODERATE (CVSS 4.8) http request smuggling vulnerability (CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')) affecting Undertow core libraries in the Maven ecosystem. The issue involves http request smuggling in undertow. Remediation is available by upgrading affected packages to version 2.2.0.Final.

CVE-2020-10687 at a Glance

CVE Identifier CVE-2020-10687
GHSA Identifier GHSA-p9w3-gwc2-cr49
Severity MODERATE
CVSS v3.1 Base Score 4.8
CWE Classification CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Affected Product Undertow core
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 4.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2020-10687

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

io.undertow:undertow-core fixed: 2.2.0.Final 
<dependency>
    <groupId>io.undertow</groupId>
    <artifactId>undertow-core</artifactId>
    <version>2.2.0.Final</version>
</dependency>
Verify Direct and Transitive Dependencies

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

mvn dependency:tree -Dincludes=io.undertow

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2020-10687, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=io.undertow

Analyze the terminal output to locate any version of Undertow core in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.2.0.Final), your application is affected.

Note: The mvn dependency:tree -Dincludes=io.undertow command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

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 Undertow core, 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

A flaw was discovered in all versions of Undertow before Undertow 2.2.0.Final, where HTTP request smuggling related to CVE-2017-2666 is possible against HTTP/1.x and HTTP/2 due to permitting invalid characters in an HTTP request. This flaw allows an attacker to poison a web-cache, perform an XSS attack, or obtain sensitive information from request other than their own.

CVE-2020-10687 Affected Undertow core Versions

1 component(s)
Fixed Versions:
2.2.0.Final
Product / Package Ecosystem Affected Versions Fixed Version
io.undertow:undertow-core
maven/io.undertow/undertow-core
Maven
< 2.2.0.Final
2.2.0.Final

References

NVD — CVE-2020-10687 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-10687
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=1785049
lists.apache.org/thread.html/r660351... WEB
https://lists.apache.org/thread.html/r6603513ea8afbf6857fd77ca5888ec8385d0af493baa4250e28c351c@%3Cdev.cxf.apache.org%3E
Undertow core Security Information SECURITY
https://security.netapp.com/advisory/ntap-20220210-0015

Frequently Asked Questions

What is CVE-2020-10687?
CVE-2020-10687 is a security vulnerability in Undertow core involving HTTP Request Smuggling in Undertow under CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling').
Which Undertow core versions are affected?
Affected versions include releases prior to 2.2.0.Final across affected packages: io.undertow:undertow-core.
What version fixes CVE-2020-10687?
Upgrading to 2.2.0.Final (or the latest patched release for your respective branch) resolves the vulnerability.
Is undertow-core affected?
Yes, io.undertow:undertow-core is affected in releases prior to 2.2.0.Final. Upgrade your dependency to 2.2.0.Final or later.
What is the CVSS score of CVE-2020-10687?
CVE-2020-10687 has a CVSS v3.1 base score of 4.8 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N.
What CWE is associated with CVE-2020-10687?
CVE-2020-10687 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 Maven dependencies for CVE-2020-10687?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=io.undertow'. 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-p9w3-gwc2-cr49",
  "modified" : "2022-02-11T21:12:07Z",
  "published" : "2021-04-30T17:28:52Z",
  "aliases" : [ "CVE-2020-10687" ],
  "summary" : "HTTP Request Smuggling in Undertow",
  "details" : "A flaw was discovered in all versions of Undertow before Undertow 2.2.0.Final, where HTTP request smuggling related to CVE-2017-2666 is possible against HTTP/1.x and HTTP/2 due to permitting invalid characters in an HTTP request. This flaw allows an attacker to poison a web-cache, perform an XSS attack, or obtain sensitive information from request other than their own.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "io.undertow:undertow-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.2.0.Final"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 2.1.0.Final"
    }
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-10687"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=1785049"
  }, {
    "type" : "WEB",
    "url" : "https://lists.apache.org/thread.html/r6603513ea8afbf6857fd77ca5888ec8385d0af493baa4250e28c351c@%3Cdev.cxf.apache.org%3E"
  }, {
    "type" : "WEB",
    "url" : "https://security.netapp.com/advisory/ntap-20220210-0015"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-444" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-04-28T16:14:25Z",
    "nvd_published_at" : "2020-09-23T13:15:00Z"
  }
}