Headline
GHSA-683x-4444-jxh8: Improper Restriction of XML External Entity Reference in org.cyclonedx:cyclonedx-core-java
Impact
Before deserializing CycloneDX Bill of Materials in XML format, cyclonedx-core-java leverages XPath expressions to determine the schema version of the BOM. The DocumentBuilderFactory
used to evaluate XPath expressions was not configured securely, making the library vulnerable to XML External Entity (XXE) injection.
XXE injection can be exploited to exfiltrate local file content, or perform Server Side Request Forgery (SSRF) to access infrastructure adjacent to the vulnerable application.
PoC
import org.cyclonedx.parsers.XmlParser;
class Poc {
public static void main(String[] args) {
// Will throw org.cyclonedx.exception.ParseException: java.net.ConnectException: Connection refused
new XmlParser().parse("""
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE bom [<!ENTITY % sp SYSTEM "https://localhost:1010/does-not-exist/file.dtd"> %sp;]>
<bom xmlns="http://cyclonedx.org/schema/bom/1.5"/>
""".getBytes());
}
}
Patches
The vulnerability has been fixed in cyclonedx-core-java version 0.9.4.
Workarounds
If feasible, applications can reject XML documents before handing them to cyclonedx-core-java for parsing. This may be an option if incoming CycloneDX BOMs are known to be in JSON format.
References
- Issue was fixed via https://github.com/CycloneDX/cyclonedx-core-java/pull/434
- Issue was introduced via https://github.com/CycloneDX/cyclonedx-core-java/commit/162aa594f347b3f612fe0a45071693c3cd398ce9
- https://owasp.org/www-community/vulnerabilities/XML_External_Entity_(XXE)_Processing
- https://cheatsheetseries.owasp.org/cheatsheets/XML_External_Entity_Prevention_Cheat_Sheet.html#xpathexpression
- GitHub Advisory Database
- GitHub Reviewed
- CVE-2024-38374
Improper Restriction of XML External Entity Reference in org.cyclonedx:cyclonedx-core-java
Package
maven org.cyclonedx:cyclonedx-core-java (Maven)
Affected versions
>= 2.1.0, < 9.0.4
Impact
Before deserializing CycloneDX Bill of Materials in XML format, cyclonedx-core-java leverages XPath expressions to determine the schema version of the BOM. The DocumentBuilderFactory used to evaluate XPath expressions was not configured securely, making the library vulnerable to XML External Entity (XXE) injection.
XXE injection can be exploited to exfiltrate local file content, or perform Server Side Request Forgery (SSRF) to access infrastructure adjacent to the vulnerable application.
PoC
import org.cyclonedx.parsers.XmlParser;
class Poc {
public static void main(String\[\] args) {
// Will throw org.cyclonedx.exception.ParseException: java.net.ConnectException: Connection refused
new XmlParser().parse("""
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE bom \[<!ENTITY % sp SYSTEM "https://localhost:1010/does-not-exist/file.dtd"> %sp;\]>
<bom xmlns="http://cyclonedx.org/schema/bom/1.5"/>
""".getBytes());
}
}
Patches
The vulnerability has been fixed in cyclonedx-core-java version 0.9.4.
Workarounds
If feasible, applications can reject XML documents before handing them to cyclonedx-core-java for parsing.
This may be an option if incoming CycloneDX BOMs are known to be in JSON format.
References
- Issue was fixed via CycloneDX/cyclonedx-core-java#434
- Issue was introduced via CycloneDX/cyclonedx-core-java@162aa59
- https://owasp.org/www-community/vulnerabilities/XML_External_Entity_(XXE)_Processing
- https://cheatsheetseries.owasp.org/cheatsheets/XML_External_Entity_Prevention_Cheat_Sheet.html#xpathexpression
References
- GHSA-683x-4444-jxh8
Published to the GitHub Advisory Database
Jun 24, 2024
Last updated
Jun 24, 2024