CVE-2020-1745: Undertow core Improper Authorization Vulnerability

HIGH
Advisory Identifier: GHSA-gv2w-88hx-8m9r
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CVSS 8.6
CWE-285
Published
Advisory Summary

CVE-2020-1745 is a HIGH (CVSS 8.6) improper authorization vulnerability (CWE-285: Improper Authorization) affecting Undertow core libraries in the Maven ecosystem. The issue involves improper authorization in undertoe. Remediation is available by upgrading affected packages to version 2.0.30.

CVE-2020-1745 at a Glance

CVE Identifier CVE-2020-1745
GHSA Identifier GHSA-gv2w-88hx-8m9r
Severity HIGH
CVSS v3.1 Base Score 8.6
CWE Classification CWE-285: Improper Authorization
Affected Product Undertow core
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 8.6

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L).

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

How to Fix CVE-2020-1745

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: 2.0.30 
<dependency>
    <groupId>io.undertow</groupId>
    <artifactId>undertow-core</artifactId>
    <version>2.0.30</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-2020-1745, 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 2.0.30), 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-285: Improper Authorization, where the product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. 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 file inclusion vulnerability was found in the AJP connector enabled with a default AJP configuration port of 8009 in Undertow version 2.0.29.Final and before and was fixed in 2.0.30.Final. A remote, unauthenticated attacker could exploit this vulnerability to read web application files from a vulnerable server. In instances where the vulnerable server allows file uploads, an attacker could upload malicious JavaServer Pages (JSP) code within a variety of file types and trigger this vulnerability to gain remote code execution.

CVE-2020-1745 Affected Undertow core Versions

1 component(s)
Fixed Versions:
2.0.30
Product / Package Ecosystem Affected Versions Fixed Version
io.undertow:undertow-core
maven/io.undertow/undertow-core
Maven
< 2.0.30
2.0.30

References

NVD — CVE-2020-1745 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-1745
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-1745
meterpreter.org/cve-2020-1938-apach... WEB
https://meterpreter.org/cve-2020-1938-apache-tomcat-ajp-connector-remote-code-execution-vulnerability-alert
www.cnvd.org.cn/webinfo/show/5415 WEB
https://www.cnvd.org.cn/webinfo/show/5415
www.tenable.com/blog/cve-2020-1938-... WEB
https://www.tenable.com/blog/cve-2020-1938-ghostcat-apache-tomcat-ajp-file-readinclusion-vulnerability-cnvd-2020-10487

Frequently Asked Questions

What is CVE-2020-1745?
CVE-2020-1745 is a security vulnerability in Undertow core involving Improper Authorization in Undertoe under CWE-285: Improper Authorization.
Which Undertow core versions are affected?
Affected versions include releases prior to 2.0.30 across affected packages: io.undertow:undertow-core.
What version fixes CVE-2020-1745?
Upgrading to 2.0.30 (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 2.0.30. Upgrade your dependency to 2.0.30 or later.
What is the CVSS score of CVE-2020-1745?
CVE-2020-1745 has a CVSS v3.1 base score of 8.6 (HIGH) with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L.
What CWE is associated with CVE-2020-1745?
CVE-2020-1745 is classified under CWE-285: Improper Authorization (The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.).
How can I check Maven dependencies for CVE-2020-1745?
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-gv2w-88hx-8m9r",
  "modified" : "2022-06-24T01:25:23Z",
  "published" : "2022-05-24T17:16:46Z",
  "aliases" : [ "CVE-2020-1745" ],
  "summary" : "Improper Authorization in Undertoe",
  "details" : "A file inclusion vulnerability was found in the AJP connector enabled with a default AJP configuration port of 8009 in Undertow version 2.0.29.Final and before and was fixed in 2.0.30.Final. A remote, unauthenticated attacker could exploit this vulnerability to read web application files from a vulnerable server. In instances where the vulnerable server allows file uploads, an attacker could upload malicious JavaServer Pages (JSP) code within a variety of file types and trigger this vulnerability to gain remote code execution.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "io.undertow:undertow-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.0.30"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 2.0.29"
    }
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-1745"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-1745"
  }, {
    "type" : "WEB",
    "url" : "https://meterpreter.org/cve-2020-1938-apache-tomcat-ajp-connector-remote-code-execution-vulnerability-alert"
  }, {
    "type" : "WEB",
    "url" : "https://www.cnvd.org.cn/webinfo/show/5415"
  }, {
    "type" : "WEB",
    "url" : "https://www.tenable.com/blog/cve-2020-1938-ghostcat-apache-tomcat-ajp-file-readinclusion-vulnerability-cnvd-2020-10487"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-285" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-06-24T01:25:23Z",
    "nvd_published_at" : "2020-04-28T15:15:00Z"
  }
}