CVE-2019-5427: C3p0 Billion Laughs Attack Vulnerability

HIGH
Advisory Identifier: GHSA-84p2-vf58-xhxv
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CVSS 7.5
CWE-776
Published
Advisory Summary

CVE-2019-5427 is a HIGH (CVSS 7.5) billion laughs attack vulnerability (CWE-776: Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')) affecting C3p0 libraries in the Maven ecosystem. The issue involves billion laughs attack in c3p0. Remediation is available by upgrading affected packages to version 0.9.5.4.

CVE-2019-5427 at a Glance

CVE Identifier CVE-2019-5427
GHSA Identifier GHSA-84p2-vf58-xhxv
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-776: Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
Affected Product C3p0
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.5

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

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 None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2019-5427

To remediate this vulnerability, upgrade all affected C3p0 dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

com.mchange:c3p0 fixed: 0.9.5.4 
<dependency>
    <groupId>com.mchange</groupId>
    <artifactId>c3p0</artifactId>
    <version>0.9.5.4</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=com.mchange

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2019-5427, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=com.mchange

Analyze the terminal output to locate any version of C3p0 in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.9.5.4), your application is affected.

Note: The mvn dependency:tree -Dincludes=com.mchange 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-776: Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion'), where the product uses xml documents and allows their structure to be defined with a document type definition (dtd), but it does not properly control the number of recursive definitions of entities. In C3p0, 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

c3p0 version < 0.9.5.4 may be exploited by a billion laughs attack when loading XML configuration due to missing protections against recursive entity expansion when loading configuration.

CVE-2019-5427 Affected C3p0 Versions

1 component(s)
Fixed Versions:
0.9.5.4
Product / Package Ecosystem Affected Versions Fixed Version
com.mchange:c3p0
maven/com.mchange/c3p0
Maven
< 0.9.5.4
0.9.5.4

References

NVD — CVE-2019-5427 NVD
https://nvd.nist.gov/vuln/detail/CVE-2019-5427
hackerone.com/reports/509315 WEB
https://hackerone.com/reports/509315
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BFIVX6HOVNLAM7W3SUAMHYRNLCVQSAWR
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MQ47OFV57Y2DAHMGA5H3JOL4WHRWRFN4
C3p0 Security Information SECURITY
https://www.oracle.com/security-alerts/cpuapr2020.html
C3p0 Security Information SECURITY
https://www.oracle.com/security-alerts/cpujan2021.html
C3p0 Security Information SECURITY
https://www.oracle.com/security-alerts/cpujul2020.html
C3p0 Security Information SECURITY
https://www.oracle.com/security-alerts/cpuoct2020.html
C3p0 Security Information SECURITY
https://www.oracle.com/security-alerts/cpuoct2021.html

Frequently Asked Questions

What is CVE-2019-5427?
CVE-2019-5427 is a security vulnerability in C3p0 involving Billion laughs attack in c3p0 under CWE-776: Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion').
Which C3p0 versions are affected?
Affected versions include releases prior to 0.9.5.4 across affected packages: com.mchange:c3p0.
What version fixes CVE-2019-5427?
Upgrading to 0.9.5.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is c3p0 affected?
Yes, com.mchange:c3p0 is affected in releases prior to 0.9.5.4. Upgrade your dependency to 0.9.5.4 or later.
What is the CVSS score of CVE-2019-5427?
CVE-2019-5427 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2019-5427?
CVE-2019-5427 is classified under CWE-776: Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion') (The product uses XML documents and allows their structure to be defined with a Document Type Definition (DTD), but it does not properly control the number of recursive definitions of entities.).
How can I check Maven dependencies for CVE-2019-5427?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=com.mchange'. 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-84p2-vf58-xhxv",
  "modified" : "2021-04-23T20:12:41Z",
  "published" : "2019-04-23T16:03:18Z",
  "aliases" : [ "CVE-2019-5427" ],
  "summary" : "Billion laughs attack in c3p0",
  "details" : "c3p0 version < 0.9.5.4 may be exploited by a billion laughs attack when loading XML configuration due to missing protections against recursive entity expansion when loading configuration.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "com.mchange:c3p0"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.9.5.4"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.9.5.3"
    }
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2019-5427"
  }, {
    "type" : "WEB",
    "url" : "https://hackerone.com/reports/509315"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BFIVX6HOVNLAM7W3SUAMHYRNLCVQSAWR"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MQ47OFV57Y2DAHMGA5H3JOL4WHRWRFN4"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpuapr2020.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpujan2021.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpujul2020.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpuoct2020.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpuoct2021.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-776" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2019-04-23T16:01:51Z",
    "nvd_published_at" : "2019-04-22T21:29:00Z"
  }
}