CVE-2017-5661: Fop Improper Restriction Of XML External Vulnerability

HIGH
Advisory Identifier: GHSA-5hg8-r9vq-gjqp
Share
CVSS 7.3
CWE-611
Published
Advisory Summary

CVE-2017-5661 is a HIGH (CVSS 7.3) improper restriction of xml external vulnerability (CWE-611: Improper Restriction of XML External Entity Reference) affecting Fop libraries in the Maven ecosystem. The issue involves improper restriction of xml external entity reference in apache fop. Remediation is available by upgrading affected packages to version 2.2.

CVE-2017-5661 at a Glance

CVE Identifier CVE-2017-5661
GHSA Identifier GHSA-5hg8-r9vq-gjqp
Severity HIGH
CVSS v3.1 Base Score 7.3
CWE Classification CWE-611: Improper Restriction of XML External Entity Reference
Affected Product Fop
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.3

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

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

How to Fix CVE-2017-5661

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

org.apache.xmlgraphics:fop fixed: 2.2 
<dependency>
    <groupId>org.apache.xmlgraphics</groupId>
    <artifactId>fop</artifactId>
    <version>2.2</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=org.apache.xmlgraphics

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2017-5661, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.apache.xmlgraphics

Analyze the terminal output to locate any version of Fop in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.2), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.apache.xmlgraphics 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-611: Improper Restriction of XML External Entity Reference, where the product processes an xml document that can contain xml entities with uris that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output. In Fop, 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

In Apache FOP before 2.2, files lying on the filesystem of the server which uses FOP can be revealed to arbitrary users who send maliciously formed SVG files. The file types that can be shown depend on the user context in which the exploitable application is running. If the user is root a full compromise of the server - including confidential or sensitive files - would be possible. XXE can also be used to attack the availability of the server via denial of service as the references within a xml document can trivially trigger an amplification attack.

CVE-2017-5661 Affected Fop Versions

1 component(s)
Fixed Versions:
2.2
Product / Package Ecosystem Affected Versions Fixed Version
org.apache.xmlgraphics:fop
maven/org.apache.xmlgraphics/fop
Maven
< 2.2
2.2

References

NVD — CVE-2017-5661 NVD
https://nvd.nist.gov/vuln/detail/CVE-2017-5661
Fop Security Information SECURITY
https://www.tenable.com/security/tns-2021-14
Fop Security Information SECURITY
https://xmlgraphics.apache.org/security.html
Fop Security Information SECURITY
http://www.debian.org/security/2017/dsa-3864
Fop Security Information SECURITY
http://www.securityfocus.com/bid/97947

Frequently Asked Questions

What is CVE-2017-5661?
CVE-2017-5661 is a security vulnerability in Fop involving Improper Restriction of XML External Entity Reference in Apache FOP under CWE-611: Improper Restriction of XML External Entity Reference.
Which Fop versions are affected?
Affected versions include releases prior to 2.2 across affected packages: org.apache.xmlgraphics:fop.
What version fixes CVE-2017-5661?
Upgrading to 2.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is fop affected?
Yes, org.apache.xmlgraphics:fop is affected in releases prior to 2.2. Upgrade your dependency to 2.2 or later.
What is the CVSS score of CVE-2017-5661?
CVE-2017-5661 has a CVSS v3.1 base score of 7.3 (HIGH) with vector string CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:H.
What CWE is associated with CVE-2017-5661?
CVE-2017-5661 is classified under CWE-611: Improper Restriction of XML External Entity Reference (The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.).
How can I check Maven dependencies for CVE-2017-5661?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.apache.xmlgraphics'. 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-5hg8-r9vq-gjqp",
  "modified" : "2022-07-01T11:57:29Z",
  "published" : "2022-05-13T01:07:54Z",
  "aliases" : [ "CVE-2017-5661" ],
  "summary" : "Improper Restriction of XML External Entity Reference in Apache FOP",
  "details" : "In Apache FOP before 2.2, files lying on the filesystem of the server which uses FOP can be revealed to arbitrary users who send maliciously formed SVG files. The file types that can be shown depend on the user context in which the exploitable application is running. If the user is root a full compromise of the server - including confidential or sensitive files - would be possible. XXE can also be used to attack the availability of the server via denial of service as the references within a xml document can trivially trigger an amplification attack.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.apache.xmlgraphics:fop"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2017-5661"
  }, {
    "type" : "WEB",
    "url" : "https://www.tenable.com/security/tns-2021-14"
  }, {
    "type" : "WEB",
    "url" : "https://xmlgraphics.apache.org/security.html"
  }, {
    "type" : "WEB",
    "url" : "http://www.debian.org/security/2017/dsa-3864"
  }, {
    "type" : "WEB",
    "url" : "http://www.securityfocus.com/bid/97947"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-611" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-07-01T11:57:29Z",
    "nvd_published_at" : "2017-04-18T14:59:00Z"
  }
}